I like your GrowBox idea all plants in 1 container
The most I'd do is prolly only 2-3 plants @ a time..
Next time you clean it out put a small fishtank pump @ the bottom with a check valve in the line so when you need to empty it just plug it in & away you go.. :thumbsup:
Unless you'd prefer the whiskey method

I need to find a way to add & keep humidity in the box I have a fogger I use for my gecko tanks just for show effect but that would pump a bunch of moisture into the air..

hmmmmmm ghetto brainstorming :wtf: