Find out where Sasha and Malia go pee and follow them in.
In all seriousness, you can apparently call yourself male or female at any whim, any time, any length of time. Just say ‘I am/was female at that time’ when you went in and took a leak and maybe missed some. Say it’s the law, and the gestapo should back off.
Course you’ll be tried as a sex offender, and you’ll need hundreds of thousands of bucks to ride it up the ladder to keep off the list and out of jail, but someone’s gotta do it.