I'd use PAM on the enclosure and soak them in water with a couple drops of mineral oil as opposed to soap for sure. As much as I hate petco they sell a reptile spray for mites that you can actually spray onto the snakes themselves to kill any mites/eggs that are left after the soak, since you can't actually use PAM on the snakes. Use white paper towels as bedding so you can see any mites and a water bowl in each cage and that's it, keep it as simple as possible until you eradicate the mites. Good luck