This Naniwa Dressing Stone A-206 has a 600 grit and is used to de-glaze and clean the surface of a honing stone during honing and also to smooth off any chips which may occur on the edges of the stone. During the honing process metal from the razor builds up on the surface of the hone and this needs to be removed in order to ensure optimal performance.
The dressing stone should be soaked in water before use, then rubbed over the stone until any marks from the honing process are removed. It should then be rinsed and allowed to dry. When soaked they work well but we have found that if not soaked they can scratch the surface of the honing stone. Using the stone to smooth off chips will create some scoring on its surface. We have therefore found it best to use one side for taking chips out to keep the other side smooth and use it for cleaning.