That's a good idea - I hadn't thought of doing it that way. If you put a layer of pebbles in the bottom up to a couple of inches and then water up to an inch and turned it into a kind of giant humidity tray that would make double sure that they were ok!
I didn't put water in a box because I was afraid that it will be too wet without much of air circulation. I just wanted them to dry out a bit slower than in open space with lots of light and it worked for me.