I have personally used the AHG in action, and they are a little tricky, being that first you have to pack the ingredients into them to start. Then making sure the cap is screwed on just right so there are no air leaks. Finally no consistant timing on the grenade makes things hard...
One battle it blew up half way to the target, second battle blew up after 30 seconds. On the 3rd battle I threw the grenade against a wall and exploded instantly.
I think that they work best when thrown against somthing with considerable force, their effectiveness is unclear to me, maybe when it is not 20 degrees outside we will test them again and see if we can make them more effective...