If you think that you are the players enemy instead of guide maybe.

That seems like a good idea for parties that constantly exploit everything they can. One off creativity should probably be rewarded though.

Honestly if you wanna give your party a bag of holding, sticking it on a bugbear assassin who uses this tactic and then uses the bag to dispose of bodies is a fun way to introduce it.

Anything the players do, I be DM can do too, yt if it uses a niche magic item, the DM better be prepared for it to end up in the hands of the players.