Originally Posted by
izlat
Mark,
I can only say I did use oil on my Escher, then I cleaned it and have been using water lately. I get nice smooth edges either way.
Again, my experience is limited, so it is possible that my results would have been better if I had stuck to oil.
However, I think this "once you use oil you can't use water" attitude might have something to do with the... who else but the Rabbis :D They are averse to using oil, and I think if oil has been used on a stone they refuse to use it thereafter, even if cleaned. Howard had mentioned something like this in his kosher Coticule official explanation
Cheers
Ivo