I have a baby stag growing inside in a bonsai pot..nice and shallow without having to mount it. Maybe with the indoor ones, smaller chunks, doled out more frequently but not big enough to attract a whole swarm of bugs, would suffice? I'm going to try a little chunk of banana peel and see how bad it gets bug-wise and/or how successful it is.
I'm guessing that it's the sugars and potassium in the banana peel that is actually helping. Bananas in the planting hole for transplanting roses serves the same purpose...gives it a nice sugar jump-start on growth, and the potassium helps build cell structure for the growing roots.