I've always wanted a product that you could add to the swimming pool water that reacts to human urine by coloring the water immediately surrounding the pee-er. Say a neon orange or red. Over time, the colored water gets diluted and disappears. Maybe pee-shaming is what's required to stop people from doing it.
Gosh this is not gonna go well with the public. I know several kids who just can't hold pee in the pool. They'll just let it out. Also its not like the toilets are right there. You often have to get out of the pool, walk like 100 yards or down a flight of stairs. It's a PITA. Even Michael Phelps once said in an interview that very rarely competitive swimmers get out of the pool to pee.
https://blogs.wsj.com/speakeasy/2012/08/06/breaking-news-fro...