Hey guys, I bought a ceramic "steel' the other day. It was from a japanese company, it looks like white chalk. Cost me 14$. Now, it's cheap, but I never encounterd it before. It was the first they sold so the store didn't know much either. Is it good for all knives? Just for special knives(carbon steal?!)? Can it erode my knives too fast? Should I limit the stokes on it? Vice versa?