Natural Chemistry Reptile Spray (you can find it at Petco) is the way to go if you want quick relief for your BP. You can apply it straight on your BP as well as spray the whole enclosure. I'd also pick up Prevent-a-Mite (PAM) and spray your whole terrarium as a second line of defence.
Make sure you follow directions on PAM and make sure that after you treat the enclosure you wait at least an hour for the PAM to fully dissipate before putting the BP back in.
I just had mites and I used both treatments every two weeks for a month and no more mites.Good luck!