Oh dear Jim, you are out of touch. Australian building codes prescribe safety levels for all glass installations particularly those which represent risk to the public, eg.shop windows which are required to be re- inforced, tempered, laminated or otherwise fitted with film so that the risk of sharding and splintering is minimised greatly.
Good luck with trying to break a shop window these days. Starring and cracks usually record the drunken oaf who tried it whilst on the piss.
Your Discombobulating flash bang would bounce off.
Back to that old drawing board, eh?
Oh, by the way, I omitted to remind you that your grenade is designed to be non- penetrating, for very obvious reasons, so it really would be quite useless for the purpose you have suggested.