A whetstone is the best tool for manual sharpening of Japanese-style knives. It is important to choose the right whetstone according to the situation of the knife: - Stone grit up to #1000 - rough sharpening, sharpening angle restoration, spot repair; - Stone grit #1000 to #3000 - daily sharpening; - Stone grit #3000 to #10000 - final sharpening and finishing, polishing; Place the stone in water for 5-10 minutes before use. Japanese kitchen knives generally have a sharpening angle of 15 degrees, European knives have a sharpening angle of 20 degrees. Before sharpening, read the sharpening instructions provided by the knife manufacturer. There is no need to clean or dry the stone during sharpening. If necessary, additional water can be sprinkled on the stone. After use, clean the whetstone under running water and dry it.