Another "weapon" you might well be carrying is a comb. Slashing with a comb -- lengthwise to the comb, not side to side like you use it -- can be as effective as a knife. A "rat-tail" comb CAN be used as a knife. A hairbrush can also be effective, especially the kind with only a few hard bristles, if you wield slash with it and go for the eyes. Jabbing -- hard! -- with a hair brush can also work.