Quote Originally Posted by MarkS View Post
I disagree, I think it's better to get rid of the substrate and spay the cage. One of the nice things about PAM is that it stays effective for a long time. If you spray the substrate and then later dump the substrate when you clean you're getting rid of some of the mite killing power.
PAM instructions specifically state to not spray directly on the cage surface, substrate only. I get your point, but a little goes a long way so there isn't much waste in a second spraying after a substrate change. However, I would still dump infested bedding and then spray new bedding, to reduce the parasite load as quickly as possible.