I was taught in herbal school that Plantain (yes, the Plantago spp, mostly major and lanceolata) helped draw out the poisons when externally applied. Many internal uses too, and I used it with great success for people who have huge allergies with beestings, worked better than Benadryl! More here:
http://herballegacy.com/Plantain_Ahlborn.html Incidentally, the school has on file many cases of really severe infections that Plantain completely healed gently and quickly. You can use it fresh/chewed (preferably by the person with the wound) or tinctured fresh in vodka - dried doesn't seem to work.