I do not add a substrate. I do mist them as much as I mist mantids and they will drink and bathe in a similar fashion. I give them plenty of sticks and leaves to climb on. They have trouble climbing the sides of a container until they lay some web. The web looks real messy and gets littered with dead feeders. I try to leave it so they can grip, even if it looks nasty, only picking the feeders out if I can. Once every couple of weeks, I clear the silk out if there is too much of it. Sometimes they build their bed where a container opens, so I just cut a hole in another spot if they do that.
I might design some better containers with grippable walls, but that will give me less visibility into their home. I have a feeling that they will web it all up anyway. lol