the reptile in just barely soapy water kills most of the mites on the reptile. This works great with snakes and lizards that deal well with water.
I think...that Provent stops the growth of chiton so that eggs don't hatch, nymphs don't become adults, etc. It doesn't necesarrily kill adults, just stops the process of hatching and metamorphasis (sp?).
Black Knight spray kills the mites that are alive in the cage and on the adults. Thing is, I only know it works on snakes, not necesarrily with your critters. The thing about Black Knight is that it isn't approved for use on reptiles. I use it for mine, but I can't really say you should.
Go to VPI.com and find their article "The War against Mites". Print it out and keep it on file. It's the best article there is for hobbiests to have on file for mite problems. I keep it right next to my snake cages.
Doug T
War Against Mites