I did something similar in N.O. during Mardi Gras called the gallon challenge. Not with milk though.
On Mardi Gras day, we'd get dropped off in the Marigny with a gallon jug...half vodka, half o.j. The idea was to drink it all by the time we walked to 7th, or 8th street.
I face planted at Lee Circle and woke up in the back of a truck. Don't remember half the day.