Warning: Excellent prank inspiration ahead.
Note: Submissions have been edited for length and/or clarity.
A gooey hand sanitizer swap:
“One of my coworkers is a germaphobe, so I replaced the hand sanitizer with lube and added some green food coloring to make it actually look like the sanitizer that was originally in the bottle. He was so confused when it wouldn't rub into his hands.” —molliem49931721d
See one Redditor's version of this prank here.
u/LetterExperiment230 / Via reddit.com