dude you dont have to agree with me but by no means should barrels even be in this game!!! they want technical perfection well barrelmancy certainly isn't included in 5e d&d
I don't disagree with you regarding "barrelmancy" but I think the guy was referring to covering up the vents in a particular room which prevents flammable grease from coming out of them when a trap is sprung. Realism issues aside, I'm fine with that and crates work just as well as barrels.
