And no, this post title has nothing to do with alcohol-- at least not directly. Let me put it into context: All matriculated Oxford students take a series of exams at the end of their studies in order to receive their degrees. These rigorous exams are taken over several days, each day lasting a few hours. Students are required to dress in subfusc, or academic gowns. As you can imagine, it is a very grueling process for students to go through. Basically, their whole Oxford degree rides on these exams.
Needless to say, it's a pretty big deal when students finally finish their exams. People often wait outside the School of Exams to congratulate their friends on finishing their tests. The tradition called "trashing" is when you spray your friends with champagne and throw confetti on them. Some people take it to extremes and also spray silly string or shaving cream on them. They can also throw various items on their friends such as water balloons, flour, tomatoes, etc. It's quite messy, but also very entertaining to watch.
Even though I don't have any exams to take, it was still fun trashing my friends.