If you do a lot of looking there is a large amount of data on pesticides done on brown snakes. They were trying to kill them with spraying but the research is sound, just backwards I would look for this data and then start there. I hope you have a background in chemistry as the things you don't know CAN hurt you.

Testing on yourself may or may not have the desired results look at P-A-M it is looking more and more that Permethrin is a human carcinogen, but there is no evidence that it has any carcinogenic effects on snakes.