Some of the videos I watched suggested soaking the stone for 12-15 minutes prior to use. One suggested using vegetable oil on the surface versus water/soaking (I used water and presoaking it for 15-minutes). So instead of a simple 'out-of-the-box-and-use' approach, it required a bit of research before sharpening a knife. Otherwise I would have given this product a 5-star rating.
The Chef’s Choice 476 2-Stage Sharpener transforms your weary kitchen, hunting and pocket knives into razor sharp cutting instruments with dependable ease. The sharpener is simple in concept, solid in its fabrication and reliable in the way it goes about its business. The design is also free of right-hand bias which is good news for the lefty chefs out there. 

The most important aspect of a sharpening stone is the grit. If you have knives that have taken a beating and are either nicked up or really dull, you’ll need a courser stone to get it back into shape. And in order to put an exceptionally sharp edge on an already sharp knife, you’ll need a finer grit stone. If your knives are already in pretty good shape and just need a touch up, buying just a finer grit stone might be enough, but don’t think you can get away without a courser stone for knives that need more TLC. It is possible to buy a combination, or two-sided sharpening stone.
This is a good size stone and has the two different grits needed for knife sharpening. No instructions were included, but there are many websites with written and video instructions, so this is not an issue for most people. A fair amount of dust is generated during the sharpening process, so protect the work surface and wash the knife after sharpening is completed.
Unlike my choice for Best Manual Sharpener, the Chef’s Choice 15 was a slam dunk for the category of Best Electric Sharpener. Not only does it come fully loaded with almost everything you could think of, it also received extremely positive consumer reviews. As usual, it will take a little more space to tell you about something as awesome as this knife sharpener.
Vielsalm Coticule on the other hand generally occurs in much more narrow layers sandwiched between the slate layer and the Belgian Blue layer and thus, it is both less plentiful and more expensive than Belgian Blue stone. Also, Coticule is divided into different grades and sometimes displays blemishes on the surface due to its proximity to the slate layer. Furthermore, it is somewhat harder than Belgium Blue stone and, due to its brittleness, it is bonded to a substrate layer of hard slate prior to sale to prevent the stone from breaking during use.
By employing separate sharpening slots, the ProntoPro 4643 is capable of sharpening both older European-style knives (such as from Wüsthof and Henckels) and Japanese-style knives (such as from Mac—which makes our favorite chef’s knife—and Shun). The difference is in the angle of the bevel that forms the cutting edge: Traditional European knives have roughly 20-degree bevels, while Japanese knives have roughly 15-degree ones. If you own both types of knife, or if you do a lot of heavy work in the kitchen (like chopping up chicken carcasses), you’ll appreciate this feature, as a 20-degree bevel is best for tough jobs. Note, though, that Wüsthof and Henckels have stopped making 20-degree knives, having switched to 15-degree or 12-degree designs exclusively in 2011; the reason is that for all but the heaviest tasks, these more-acute bevels cut better and, with the ongoing improvements in steel alloys, hold their edges for just as long.
The type of stone refers to the material it is made with. You can find many different types, including diamond, ceramic, natural stone, and synthetic. I would only suggest diamond if you’re planning to be sharpening only ceramic knives. Many of the stones you’ll find on Amazon or other retails are made of Corundum, which is a crystalline form of aluminium oxide. It’s a fine choice for a beginner sharpening stone.
Chefs will do this every day, and there's no reason you shouldn't too. Before cooking, or after you've done the washing up, honing your knife will help keep it in good condition. "When you're using a honing steel, you're not actually removing any metal at all, just re-straightening that edge, to get it back in line," says Authbert. Remember that you'll still need to sharpen it every two or three months. 
I purchased this set together with the 400/1000 grit stone assuming that some of my knives were quite dull and would need work on a coarse grit stone. Premium Whetstone Sharpening Stone 2 Side Grit 400/1000 | Knife Sharpener Waterstone with NonSlip Rubber Base & Flattening Stone. This is my first wetstone. First off I tried to sharpen my Chicago Cutlery boning knife. This knife is nearly thirty years old, has been abused in may ways and was quite dull. It was very difficult for me to get a burr on this blade, which I attribute to poor technique. Next I moved on to my Henckels Professional S paring and chef's knives. The paring knife was moderately sharp and was modestly improved after working over all three grits of stone. It would cut paper but again it was difficult to develop a burr with this blade. Undaunted I switched to the chef's knife. This knife is twenty years old and has never been professionally re-sharpened. I have sharpened it twice with a Lanksey sharpening system which marred the finish but did put a good edge on the blade. Lansky Standard Coarse Sharpening System with Fine Hones. The chef's knife was moderately dull and had several pits visible on the cutting surface. I modified my technique for passing the knife over the stone and worked the chef's knife over the 400 grit stone aggressively and eventually I was able to get a burr to form from the tip of the knife all the way to the handle. From there it was a simple process of reforming the burr on the 1000 grit stone and then finishing on the 6000. After sharpening, the chef's knife easily and cleanly slices a tomato with very light pressure and is in my opinion very sharp. Not sushi knife sharp but more than enough for the chopping and slicing I expect of it. I'm looking forward to going back and working both the boning knife and the paring knife over again. Don't expect a good result from this product the first time you use it. Watch videos on using a wetstone, expect to spend at least twenty minutes per knife at first, and practice forming a burr. If you can form a burr, you will be able to successfully sharpen your knife.
There are consumers that used the Chosera stones for years with amazing results. Some even bought the different lines of Chosera stones since it can be hard to choose a favorite (just like the Naniwa Chosera 800 Grit Stone which is also highly recommended) and all serves different sharpening purposes. But many agreed that the Chosera 1,000-Grit is an excellent stone to create a new bevel on straight edge razors.
Scissors get dull, too, but many sharpeners can’t handle their unique shape. This easy-to-use manual sharpener can handle scissor easily, and will also sharpen all of your non-serrated knives with ease. It’s ergonomically designed for either right- or left-hand use and has a protective finger guard so you can safely sharpen all the knives in the block.
On the other hand, the surfaces of knives that have been looked after may blacken a little, but this is a different type of iron oxide than ordinary reddish rust. This black oxidation is mainly triiron tetraoxide (Fe3O4). It coats the surface of the metal and prevents ordinary rust from getting in. It will not discolor food and poses no threat to hygiene.