I have thought about that idea, but how do you guys get those nasty maggots out? Its really gross! If I was a dart frog, I don't know if I'd want to eat them after they've been wallowing in that stinky medium! I don't want the flies to buzz all over the place either.
Get a cheep plastic paint brush (those bright neon ones carried by dollar stores) and just pick them off the walls of your container and wash them off in some water. You can even dust the larva to make it eaiser for the frogs to pick them off.