want to keep the loo clean? use psychology.

"There’s something of a surprise waiting at the bottom of the urinals in Amsterdam’s Schiphol Airport: an etched image of a fly. At first glance, one might be forgiven for thinking it real. Then one notices that all the urinals have one, and the fly is always in the same position, just above the urinal drain and off to the left. It turns out that men, in their urinal behaviour, cannot resist peeing on things, especially if they look as though they might wash away. According to Klaus Reichardt, who invented the waterless urinal and now runs a company that sells this technology, nothing works as effectively as getting men to aim in the right place.‘Guys are simple-minded and love to play with their urine stream, so you put something in the toilet bowl and they’ll aim at that,’ says Reichardt. ‘It could be anything. I’ve seen a golf flag, a bee, a little tree. It just happens that at Schiphol it’s a fly" https://worksthatwork.com/1/urinal-fly