I like that egg crate idea!
I keep my reptariums on tables. Indoors I use currigated pvc roofing material (like you see over carports and greenhouses) under my reptariums and put the tables up on concrete blocks at one end. Makes the water run down in the currigations like little gutters into catch tubs at one end of the tables. Outdoors I make tables that look kind of like ladders where each pair of rungs supports a potted plant and then the mist just rains right through the bottom of the cages onto the lawn...