More like Bag of Scolding.
Dont know how many of you have tried to weaponize one of these bad boys, but I'm here to share my experience:
1: Fill bag of Holding with water, or other liquid. Play a rogue or other sneaky build. Sneak up behind enemy. Quickly pull bag over enemy head and pull the drawstring as tight as possible until enemy stops moving. Then hold tighter for a few more minutes, just to be sure.
2: Fill with spikey bits. Like calltrops. Perform same actions as in first scenario, but enemy will not drown, so just tie off the draw strings and watch them suffer. Beat them up while they flail around in confusion. Or don't. Makes the hilarity last longer.
3: I call this one "The Portable Elevator". It is a bit of an in depth project, but worth the results if you can pull it off.
Find a spot to place your bag of holding where it will be secured and capable of launching needed item/PCs/NPCs.
Put bottle of Alchemists Fire in bag.
Draw strings closed as tight as possible and tie them off.
Hit bag, shattering bottle of Alchemists Fire.
Place shield over opening of bag.
Place item/person/whathaveyou on shield.
Any other good ones out there? Ive heard the colapsing arrow with a portable hole and bag of holding wrapped around it so it makes a black hole on impact, Im looking for more inventive uses.
Like putting a kobold in a bag of holding filled with caltrops and just shaking it until he talks.