Sab, I need to disagree with you. Gauze is not very attainable for small groups and especially hermit builds.
I do agree that leeches should remain as they are. But I think some in-between method for healing would make the game more interesting and fun.
Traditionally herbs would be used for this effect. Perhaps willow bark (aspirin), as I think has been suggested before, would work.
Cheers to your character's health!