Sonic Shower thought: if the Dominion had sent a battalion of blue barrels at the Klingon Empire during the war, the Federation Alliance would have quickly crumbled.
I mean, so many broken backed Klingons after their natural enemies, the blue barrels, dispatched them on the field of battle. Lying there helpless, begging for the Hegh'bat.
I suppose in that way, the blue barrels were the Bane to the Klingons' Batman.