I feel ya! I bounce from subject to subject in writing and I get where you are coming from. Lately I have been drawn to things that I would not normally be drawn to in terms of research, things that necessarily have anything immediately to do with what I am trying to write. It's frustrating, but...
What about using snake venom to combat snake venom? That would be considered an a venom vaccine, no different than your typical vaccines.
There's also several theories on using plant poison to cancel out plant poison but from what I have read so far, without any refinement it is not effective...