Give your leech character Bloodletting (Witchcraft), and they can use it on the other character, who can then either stand or run around or create a blood surface. If your other character learns Bloodletting, it is pretty much an instant heal for the leech outside combat.
Alternately, just head out the gate west of the harbour. There is lots of blood there before you get to the mined section of the beach or higher level orcs.
