Derivative of oft. used "Get a room" (often uttered to couples passionately going at it in full view of the general public). Used in the context "get a broom (and clean up that mess!)", often said to a friend or passer by, when a shambles or a man/woman is in view. A mess of course, is a commonly used term for somebody whose life is in disrepear, or those who have consumed far too many noxious substances, perhaps over a long period of time.
Matt stumbled into the room with a 'J' in one hand, and a Special brew in the other, spouting on about how good fightstar really are. "Get-a-broom!", I exclaimed to my pals next to me, nodding my head in Matt's general direction.