i got your problem fix right here
go to a store like walmart or a pet store
get HARTZ FLEA & TICK POWDER for CATS
put the snakes infected in their own bag and dump a good coating onto the snake , tie off the bag leave in over night .
then clean your cages /tubs whatever you use . and sprinkle some in with your substrate . the next day look over the snake to make sure all are dead and place snake back in its cage .
this way even works on eliminating eggs from producing cause it gets under the scales .
1 night in a bag an all mites on snake are dead ..
i use it religously and i dont use anything else and i dont have out breaks .
and its perfectly harmless to the snakes ..