We have a lot of these in the military (M203 blank adapter, box of grid squares, chemlight batteries, testing the armor on gun trucks or the shocks on armor lik

We have a lot of these in the military (M203 blank adapter, box of grid squares, chemlight batteries, testing the armor on gun trucks or the shocks on armor like APCs or tanks, etc). But my favorite by far was convincing a FNG to collect a few exhaust samples from the Bradleys. This guy was a friend of mine in the civilian world and a really smart dude, but man he fell hook, line, and sinker for that one. He would climb up there on the vehicle with a trash bag, cover the massive exhaust port, then tell the driver to fire it up. It just blew thick, black engine smoke all over him, covering him in soot. Several times. When he finally managed to get a big cloud of exhaust in the trash bag (with the whole platoon standing around watching), I took it and opened the bag and looked in there and said, "Nah, man, this one's not quite good enough, gotta get another one"... Finally he ended up walking across the whole formation to the motor sergeant with this giant transparent trash bag full of engine exhaust, covered head to toe in black gunk, totally proud that he finally got a good sample.