The Kansas City Chiefs have the portable toilet drill, in which a receiver enters a portable toilet in full uniform, sits down and waits for the door to be opened by another player, at which point a football is fired into the opening and the receiver must catch it. The goal is apparently to increase concentration.
From a Boston Globe article on NFL training camp hijinks.
It also says that the drill originated with the Pats.
I love the use of the word “apparently.”