The manufacturers actually answered this for me in a good video:
I'm hoping this could be a very cost effective airsoft nade. I also like the idea of not only BBs, but flour or powder being used in them. It would be hard for people to not take a hit when they have flour on their legs ?
Well maybe the negativity is valid - I just tested it and it didn't work without some lube and a little sanding on the lower container to get it to consistently go off. It does seem good though as a reusable with a decent "pop". The bang is not much more than a small balloon going off, but I have found most airsoft nades too loud to be thrown as part of a game, but maybe I'm a namby pamby like that.