Hi,
I'd probably just use a bath of 86f water with a spot of dish soap in it to drown them.
Check around the snakes eye sockets and heat pits as well as the vent - the little beggars get everywhere.
You also need to treat all the enclosures of any other reptiles you have as mites travel a fair distance to find food and lay eggs.
One more warning - P.A.M. is extremely potent stuff.
Any insects or spiders etc have to be removed from the rooms being treated or it will kill them.
Do not ignore the warning about removing the waterbowls and snakes before treating the enclosure.
dr del