I swear I'm the QUEEN of poison ivy! I not only get it horribly every year (and usually more than once each season)...I also have 3 acres of which about 1 1/2 acres of it is wooded and full of the ivy! Last year we bought two pygmy goats and this year have put them on weed duty so we don't have as much weedeating to do. I didn't realize they would eat poison ivy, but they do! Usually within a day or two, they have everything eaten down to the pine needles (we only have pines). However, I'm not sure it will keep it from coming back since the roots are still in the ground...I guess only time will tell on that.
I once borrowed a book from a friend that had a recipe for poison ivy killer in it but can't remember it exactly. It called for boiling water and rock salt and I think that was all. You mixed them together and then sprayed it on the plant. I will try to get the recipe from her today and post it on here.
Good luck!