One of my buds is a former Navy Seal who I observed sharpening his jack knife using circular and figure 8's on a fine arkansas stone with minimal oil, if any, for almost an hour. The blade literally shaved the hair off of his arm and the knife whose brand I don't remember wasn't anything special. Take a look at this article at FallKniven from Sweden. I'm wondering if the same would apply to straights and I don't use a straight.