To quite literally, shovel shit down someones throat, whether they like it or not. They dont stand a chance if you're a dirt bagger, they wont stop till you've either A. Passed out from the smell, or B. Urinated yourself from the fear of what they might do. Dirtbagging occasionally includes a spade and hand cuffs, though it doesnt have to.
Hey dude, what are you doin with that..
OH MY GO-MMPF