I can't bring myself to use oil on a coticule. I seem to remember someone saying they got great results with theirs but I'm not going there. Escher labels say to avoid oil or grease so we know to forget oil on those. I have an old Tam that is supposed to be okay with oil or water and I might talk myself into giving that a try someday. Arkies are all I've ever used oil on. I've got a jug of Smith's honing oil I've had forever. Seems to be good but probably just overpriced mineral oil with a different label on the bottle. :)