This actually sounds like a blast to play.
My contribution: Not long before my time, the boys in my high school swam in the nude daily in swim class.
mmm
We did this my senior year (88-89) and we even called it The Assassination Game as well. We had these guns that fired soft red bullets as our weapon of choice though anything that shot a soft projectile was pretty much accepted. One friend even wrote up a whole page of rules for people playing (In school was not allowed but parking lot and off grounds was free for all). When a VP found one of the players with the page of rules it kind of put a damper on the game.