If you're using an oilstone to sharpen your knives, it's important to keep it clean and free of debris. The best way to clean an oilstone is to use a honing oil. Honing oil is a light lubricant that will help dislodge any particles that are stuck in the pores of the stone. Simply pour a small amount of honing oil onto the stone and use a soft cloth to wipe it away. You can also use mineral spirits or white vinegar as substitutes for honing oil.