An idea that just popped into my head; a bit weird, but maybe fun.
This file gives you true bladder control; your bladder controls your mind completely. As soon as you feel the need to pee, you start to become more suggestible and obedient. The fuller you feel, the harder it becomes to question what you are told or to disobey any direct command. Of course, this could be problematic (and I generally disapprove of files that let anyone control you). So you will always know that if someone gives a command that you're opposed to, you can always take back your free will by emptying your bladder. Nobody else's command can take that safety mechanism away.