They drank a shot of olive oil to 'coat their stomach' before drinking the vodka. I've never heard of doing such a thing but then, I was never prone to drinking too much in bars and getting in fist fights.

It's totally one of those silly tips you'd get in college that would of course not really work. They ought to have just told her to eat a lot of bread before going out and ordering club soda and pretending he was alcoholic.