A dedicated spray bottle with a solution of 1/32 parts bleach/water is safe and effective to properly clean almost any enclosure. 32 oz. heavy duty spray bottles can be found at your local Walmart in the home hardware section.
Fill with water, add one ounce of bleach(about 2 capfuls)
Spray down enclosure
Wipe, wipe, wipe with dedicated rag or paper towels
RINSE
RINSE
RINSE until you can't smell anything in the tank/tub.
Towel dry(I leave mine out in the sun for a few minutes after the towel to completely dry)
Refill/redecorate cage
Done.