A week? I thought you have to wait 2-3 weeks before retreating? Follow the directions in the can.

Hmm... I haven't seen any mites on my boa for a few days. I think it takes a weekish for the adult mites to be gone. You could spray the substrate but if I were you I'd, switch to paper towels or newspaper until the mite are gone. Then go back to your usual substrate after 4-6 weeks at the very least.