I just got my BP, Copernicus, back from an escape a few days ago! With snakes, I say you don't find them, they sort of just show up. While BP humidity requirements aren't too particular/an absolute emergency, I'm not too sure about your BRB. But I'd say simply be patient, for snakes can go missing for months at a time, and will show up when they see fit. For instance, we found Copernicus in about a month, wrapped up under my gerbil's cage. Have you tried the flour trick? Or the plastic bags?
best of luck!