Once you're sure it's good and dry, the pests are kapoot. Then you're best bet is to cook it for a while. Then you've got brand new rock that's ready to go.
If you're in a hurry though, there's also the bleach method as well as the acid method. I first read about it here:
http://www.3reef.com/forums/live-roc...ock-37810.html
Note: I've never done either the acid or the bleach treatment.