If I have the sort that is glassy and just gets more and more mirrored with use I tend to use it on water only and then go to running water under a tap for even more buffering. Those types tend to give off really sharp edges for cotis.. But I do the heavy lifting with another rock. Sometimes the backing stone with coti slurry if the base stone has enough gas to delete the bevel scratches... Usually I will reach for a quicker but coarser coti though. It will take me awhile to figure out as the feedback seemed so wonky