To be fair, from my recollection of freshmen challenges, a cup of vinegar, a large raw onion, and a head of garlic is sufficient to either induce vomiting, or to compel the 'winner' to self-induce vomiting.
The advent of both these kind of challenges as well as Youtube have brought to light a level of durability of the human digestive tract I wouldn't have previously expected. One only needs to watch someone like skippy62able (L.A. Beast) to have their eyes opened (and possibly their gag reflex triggered). For example, witness him consuming baking soda and then drinking a glass of vinegar:
https://www.youtube.com/watch?v=3Ke1el2TsDs