I've seen someone try to do that one, it's pretty entertaining
I could drink a gallon of MILF, but it might take me a little more than an hour...
Your body can't hold a gallon of anything and not get rid of it somewhere, milk just makes it sit on your stomach that much worse.
I first learned about the milk challenge from a guy I used to work with. I guess him and his friends would do it in bars and bet people $100 bucks they couldn't do it. We go up to the fucking middle of nowhere Minnesota for work during the winter. We were at the bar one Friday night and somehow got to talk to the townies about it. Of course one of them beams up "oh, that's easy, I could do that any day?. So put $100 bucks on it! He proceeds to borrow $100 from one of his friends mom's that's there while my co-worker was running across the street to get the gallon of milk. This guy did some work and finished about 2/3 of it in around 15 minutes. Then he hit the wall and couldn't drink a drop more. He proceeded to go into the bathroom and puke. Do you know what almost a gallon of milk feels like coming out of the wrong end, especially after you've already throw a few back? Yeah, me neither, but I can tell you from what he looked like that it wasn't worth winning or losing $100 over. After that we ended up going over to that mom's hose when the bar shut down around midnight and party in her basement. It was like high school all over again. We decided to leave when she came down stairs and yelled at her son for letting one of his underage friends drink down there. Fun times.