Pew! Liquid Ass prank spray will make a room smell like farts, really foul smelling ones. According to people who have bought and used it, it's strong and it will make you gag. But it also has another use, a more noble one:
Researchers, hospitals, and programs designed to train medical professionals routinely order Liquid Ass. The stench so realistically mimics the human colon, it’s the perfect training tool to teach medical responders how to maintain focus and professional demeanor in the midst of a truly overwhelming smell. And because the stench is universally offensive, psychologists have found it’s the perfect tool for studying the effects of disgust on all sorts of human behavior, from political decision-making to health care choices.
...Kata Conde, an assistant nursing professor at MidAmerica Nazarene University in Kansas, started buying Liquid Ass for the simulation lab she runs for her students. It’s the only product she’s found that accurately captures the smells that come from our bowels, and she would know: she had a 30-year career as a nurse before becoming an instructor. Conde now uses Liquid Ass in teaching scenarios in which a patient has soiled themselves while trying to get out of a hospital bed, complete with chocolate icing to set the scene. It’s also good for practicing bowel surgeries, like colostomies, where surgeons divert some of the large intestine to a new hole in the abdomen.
“The smell hits you like a huge wall,” she says. “It’s something people react to when they first experience it. We see all kinds of faces.” In a real-life scenario, any kind of reaction to a stench like wrinkling or covering your nose would make a patient understandably embarrassed and uncomfortable. To successfully complete the simulation, students have to demonstrate that they’re capable of giving adequate care while maintaining professionalism...
According to this Quartz article, An unusual medical training tool got its start as a childish prank, it's also being used for scientific and military purposes.