Shower yes and so does Mrs. 3000. No golden showers though . Pool no, you NASTY bastards! That's just gross and it's a big reason why I don't like jumping into public pools. Now peeing in the ocean is something else and I pee in there anytime I have to go.
There is a large volume of water in a pool in the first place, and there is a good amount of chlorine. Urine is sterile anyway, therefore it isn't a big deal.
Besides, even if you don't pee in the pool, others still will.