However, due to limited natural deposits and extensive quarrying over the centuries, true, high quality, Japanese water stones are now few and far between and are very expensive. Thus, various companies are now producing synthetic Japanese Water Stones which generally have a more consistent composition and grit size than natural stones as well as often begin somewhat harder and thus, lasting a bit longer; not to mention being cheaper to purchase.
You must put the knife blade's position at the perfect angle which is called "against the stone." What's important is the blade should be facing opposite from you. Where you've determined where the bevel angle is located, then this is what you will position against the stone. It's a good idea to know the differences between various angles for certain blade uses. There's a certain height of the blade that it should be from the stone. You'll be able to find various charts on height of the blade online. Normally, for a pocket knife or kitchen knife, it'll be 17° - 22° angle against the stone. The "Rule of thumb" is the smaller the angle, the sharper the knife. Most makers will have it in the instruction or on their official website.
The little white pieces don't seem to damage my stones, though I am careful to apply the bulk of my pressure to the blade edge. They ride back and forth just fine. There is a little bit of an art to finding the right movements so the jig doesn't fall off the side of your stone but you can still use most of the stone. It's sort of angled down and away from the top corner to the opposite bottom corner
If no metal is being removed from the edge of the blade, it’s considered honing. Whereas if metal is being removed from the blade edge this is considered sharpening. Certainly, even honing will result in some microscopic amounts of metal being removed from the blade edge but not enough to be visible to the human eye, so the above definition is basically a solid one.
We tend to recommend natural Japanese water stones only to experienced users who are thoroughly familiar with the synthetic Japanese sharpening stones. Natural stones are not to everybody’s taste and there are inevitably many uncertainties with regard to their grit grade, which cannot be determined exactly, their hardness and their suitability for certain types of steel.

Let’s start with Arkansas. If you have heard about Arkansas oilstone, it uses the Novaculite stone that mined in Arkansas. The most expensive of Arkansas stone is the Hard Translucent model that begins to rare in the market. If you want to shop for Arkansas, they are available in different grade starting from Soft Arkansas, Hard Arkansas, Hard Black Arkansas and Hard Translucent Arkansas. The finest grade of Arkansas can shape such of mirror polishing edges.
This coarse grit whetstone is great for prepping old and dull knives that need to be sharpened with a fine grit stone. One of my good knives edge looked like someone had tried to chop barbed wire. After ten minutes on each side of the stone, the edge was smooth and free of imperfections. After it hit the knife with the fine grit stone, I was cutting onions and apples like hot butter! I would soak this stone for 12-24 hours before using. It sucks water like a sponge. The surface needs to be damp when you sharpen.
The composition of the stone affects the sharpness of the blade (a finer grain, usually, though not always, produces sharper blades), as does the composition of the blade (some metals take and keep an edge better than others). For example, Western kitchen knives are usually made of softer steel and take an edge angle of 20–22°, while East Asian kitchen knives are traditionally of harder steel and take an edge angle of 15–18°. The Western-style kitchen knives are generally in the range of 52–58 on the Rockwell scale, which denotes the relative hardness of a material.
Sharpening stones have been around since the dawn of civilization for a very good reason: they work. Yes, they’re more labor intensive than most electric sharpeners but they also allow you an unprecedented level of control. Once you get used to something like the Fallkniven DC3 Diamond/Ceramic Whetstone Sharpener you may never take out your electric sharpener again.
However, it should also be noted that “water stones” are generally significantly softer than oil stones and thus, water stones generally cut faster than oil stones but, they also have to be flattened more often that oil stones do. Furthermore, it should be noted that some water stones must be soaked in water for several hours prior to use whereas, others are of the “splash and sharpen” variety and thus, they only need to be soaked for a few minutes before use and then wetted down occasionally during sharpening process. Diamond hones on the other hand are more durable than either water stones or oil stones and, because they generally have a more coarse grit, they cut faster than natural whetstones. Plus, due to their construction, they never need truing and, in fact, coarse diamond hones are often used to flatten both natural and synthetic whetstones.
Put the pointed, narrow end of the sharpener up against the open end of the gut hook. The narrow, pointed end of the sharpener should face in toward the thickness of the blade, away from the edge of the gut hook. Match the angle of the sharpener to the original edge angle. This will maintain the correct sharpening angle and prevent you from getting cut by the blade tip. Hold the same angle when sharpening each side of the gut hook.  

I really like this stone. The 1000/4000 grit combination is perfect for my needs. I'm a woodturner, and belong to a club that brings in professional turners from around the world. One had an eye opening test of sharpness. He stacked around 25 new razor blades in a box with one open side. The box assured that the blades were in perfect alignment. If you looked at the blades' sharp ends head on, all you saw was black. His point was that if you can see the edge, the blade is not sharp. Any reflection from the edge, again, facing it head on, is a dull spot. My long story leads to the fact that I was able to sharpen several knives to the point of not seeing the edge. This is not the stone to use if you are trying to remove nicks from a blade. A lower grit will do that job. This is for putting a fine, "invisible" edge on the blade, and with the right technique, that's what it will do. Another thing to consider is the fact that these stones are "sacrificial" A stone wears because it is deliberately giving up dull surface particles to expose the sharp ones below them. Anyone expecting a stone to last forever is mistaken. Bottom line? I think this is a great stone that takes my knives to the level of sharpness I need in both woodworking and cooking. I also like the rubber frame it sits in, giving you much better control over the stone. Your efforts can go into sharpening without having to steady the stone on your workbench or countertop.
Selecting the proper coarseness for your sharpening stone is an important first step in sharpening your knife. Not every knife needs to start at the coarsest stone you have, on the other hand a very dull knife can not be sharpened on only your finest stone. Starting with the proper coarseness will ensure that you achieve the edge you need quickly. If your knife is very dull or has a nicked blade, start with your coarsest stone. The coarse stone removes material quickly so a poor edge can be refined quickly. However, the coarse stone must be followed up with your finer stone to refine the edge. If your knife is only slightly dull and just needs a quick touch up, starting at a medium or fine stone can save you time. Starting on a fine stone requires fewer steps but must only be used on an edge requiring little work.
However, due to limited natural deposits and extensive quarrying over the centuries, true, high quality, Japanese water stones are now few and far between and are very expensive. Thus, various companies are now producing synthetic Japanese Water Stones which generally have a more consistent composition and grit size than natural stones as well as often begin somewhat harder and thus, lasting a bit longer; not to mention being cheaper to purchase.
first time buying a sharping stone. i bought this because i wanted to sharpen kitchen knives. you have to practice to get good at it, use a knife you don't care about because you might mess it up. there is some conflicting instructions online on how to use, water or no water. read as much as you can about using stones and practice, practice , practice. look up videos on youtube and internet. i had fun using it, BUY IF YOU WANT TO LEARN here is some stuff i found, they all sound like professionals this is a video that says don't use water this is a youtube video that i watched that uses water. *informative 

Ease of use – Most people in search of a mechanical sharpener want one because they don’t want to be bothered with trying to achieve a perfect edge themselves using a stick or sharpening stone. They want predictable, first class results every time. In that case it’s important that the electric powered device is easy to use, achieves results quickly and with little effort and is designed with user safety in mind. Keep in mind too that it’s easy to apply too much pressure when using a mechanical sharpener and when that happens you’re likely to see unsatisfactory results. In addition there are subtle differences between mechanical devices designed for Asian-style knives and those designed for Western-style knives. This has to do with the sharpening angle discussed above. Don’t get an Asian sharpener if you don’t need precise control over your cuts.
I recommend it as a lightweight alternative to larger stone for smaller knives. Leather necklace is comfortable and seems strong. I conditioned it for suppleness and swim with it on tightened as a choker. Stone is small, dog-tag size. I use it with water. Functional for small folder knives and multi-tools. Not useful for large fixed blades, since you can't make a long stroke. Small to grip. I use double-sided tape on one side to keep it in place on a flat rock. Not sure of grit, seems like around 1000. It took a while, but i got my old boy scout knife sharp.