so far I have only seen or heard of Jnats working with water, some people choose to use oil, glycerine, shaving cream etc... all Jnats can work with water but once oil is used ive heard you must stick to it because it seeps into the surface of the stone. when buying a Jnat number one thing to know is that all of them are different. it does not matter if they are both from the same strata, each stone has its own minute differences from one to the other. number one thing you want from a Jnat is feedback. I use this an indication of where I am with the razor. My Ozuku is rated 5+ which I would assume is a 9+ just on a different scale. mine is not "scratchy" per say. but I have to admit I may have used that reference in the beginning before I started lapping the way I do now. I think this is something you may be able to get rid of by lapping with a higher grit stone.