As far as I know....that stuff is toxic. That's why you only use a 1" piece. If you don't have mites and you are not bringing in questionable animals...then why expose this to the animals you do have?
I read somewhere that snake mites are not native to North America. They come over with imported animals and/or thrive in places that take in these imported animals. I can't validate that so take that as you will.
I think the best way to control mites is to quarentine any incoming animals to your collection.
If there is anything the nonconformist hates worse than a conformist, it's another nonconformist who doesn't conform to the prevailing standard of nonconformity.