How do you clean a cotton strop? I sometimes go from linen with chromium oxide to my cotton strop and I think over time a little bit of the chromium oxide has come off onto the cotton. I don't think its enough to hurt anything and I can't really see green on it,its just a little bit discolored. May even just be metal particles from the blade itself. I have since started wiping my blade before I move from the chromium oxide strop to the cotton strop.