I remember a post here a while back by a guy who was taking some drug that made his urine glow in UV light. Silly fucker went into a nightclub, from memory…
I’m not going to try to put this into rhyme, but the male urethra is shaped like a P-trap. [Warning: Anatomical diagram, possibly NSFW] If you really want to get rid of that last little drop, you have to reach behind your balls and squeeze on your gundle a little bit.