I am not convinced. It seems to me as though you'd need to be sexually excited to get your john thomas into one of those things and anyway, I dress to the left...
They look like a latter day equivalent of an Elizabethan cod piece. Can you imagine the proportions they would assume if they became fashionable!
I'll just carry on peeing into a wetsuit and flush a few gallons through from the neck as I get out of the water. Then no one will ever know just how penilely challenged I am...