It might be worth buying a small pot of medical grade Manuka Honey (make sre you ge a genuine one, packed
in New Zealand. There are many fakes about!) and filling the hole with
honey, then applying a dressing over the top, which would have to be bandaged on. (I don't know if you could make that stay on, or whereabouts on the leg the wound is, but if you could find a way to keep a dressing over the honey it would be good.