if you can use pyrethrin then you might be able to use Permethrin. it is a pyrethroid. it is commonly used to kill insects. it i have used it to kill spider mites that my snakes have gotten in the past. it is commonly used in lice treatment too. it is the active ingredient in equate bedding spray. that's the walmart brand of lice treatment. it can be found by the pharmacy. it's should be under $4 a can. i'm not saying it will work but it might be worth looking into by someone with well more experience then my own.

for the treatment of snake tanks you remove the reptile and waterdish and spray over the bedding and let dry before returning said reptile. i usually spray a couple of times to make sure everything gets it. it is kinda of a dusty, dry spray evaporates pretty quckly. i used it once and the next day, maybe two, all spider mites were gone.

....or you could get some lady bugs. they eat spider mites. when you are done you can vacuum them up and keep them in the fridge.

where are do you get lady bugs you ask? well that wasn't the question!

hope this helps.

-shake