There is no such thing as a mite spray that is safe for lizards. If it's potent enough to kill the mites, then it will seriously sicken and probably kill the geckos and chameleon.
Mites need to be dealt with in an entire different manner, here's a great article:
www.anapsid.org/mites.html
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Christina Miller
Herptiles.org
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1.0 Iguana iguana - Draco
1.0 Anolis carolinensis - Duke
0.1 Eublepharis macularis - Ocelot
1.0 Cosymbotus platyurus - Baron
1.0 Cynops orientalis - Hyper
1.0 Leiocephalus schreibersi - Turbo