I would listen to Bill's advice as it is sound and effective. The only thing I would add to it is you really need to spray the outside of the cages as well. The inside of the cages are cleaned and sprayed less frequently, but the outside should be sprayed about twice a week as new mites coming in will be killed while any mites missed by the interior treatment will be killed when they try to migrate. Outside of the cage spraying is a critical step in mite control. The other thing that should be avoided is attempted mite control by using strong bleach solutions. Not only is it dangerous as you found out, but it is usually ineffective at eliminating the mite problem.

Kelly