When cleaning enclosures I have used two nesting Tupperware containers One with the lid affixed and a hole in the side for entry by a snake that was left in the enclosure at all times to be used as a hide, of sorts. When the snake was in the container I would lower another container down onto it with a hook, thereby enclosing the snake inside. I would then remove the nested containers and secure them together with duct tape.

Any other ideas, plans, or sources on trap box construction or alternative methods of securing potentially dangerous animals for routine maintenance?