From: Jackass 3D
The "Poo Cocktail" was introduced in Jackass' pilot episode—but don't worry, it's not what it sounds like. Well, not exactly what it sounds like. In that introductory episode, Knoxville locks himself in a Porta Potty, which is promptly tipped upside down.
In Jackass 3D, Steve-O is the one inside the porta potty attached to a couple of bungee cords that shake it up and down. Which is made about 100 times more sickening in three dimensions.