A whetstone or a sharpening stone is essential for keeping the blade of your knives sharp. To keep your whetstone or sharpening stone in good working order, you must clean it properly after each use. The investment of the little time it takes to clean the stone will pay off in the long run, and the stone will stay at its best performance, allowing you to have a sharp knife.
Shiny gray streaks and a coarse grit on your whetstone indicate accumulated debris. What to use to clean the stone depends on the type of stone you use and what you use while sharpening the knife. Be sure to put a towel under your whetstone during the cleaning process to catch excess particles.
Decide what you are going to use to clean your whetstone. For the sharpening process, you can use sharpening oil to sharpen the blade of your dull knife and clean the stone. Sharpening oil provides lubrication for sharpening the whetstone, reduces friction, and prevents metal fillings or metal flecks from embedding in the stone. To clean the stone, apply a small amount of oil and rub it in a circular motion across the stone. You will see metallic flecks lifting out of the pores and while this is happening, wipe the stone with a cloth or paper towel. Rinse it under running water and then dry it with a paper towel or rag.
If you are using a water-based honing oil, clean the whetstone with warm, soapy water. You can use an old toothbrush or green scouring pad to scrub the stone clean. Use the same longitudinal and circular motion.