Here’s something half-baked: In the UK, urinals in the gents (God, I can’t wait to be home and to stop having to ask for the mens room or restroom!) flush themselves on a timing mechanism so that (as long as it’s working) it gets washed out every few minutes. Here in the US, there are two types of flush that I’ve seen: a manual knob (as in the picture) or else an automatic one based on a sensor which causes it to flush when you walk away.
I don’t know what this says about our respective cultures, if anything at all, or what point you could use it to make, but I thought it might live in the analogy library until someone could work out how to use it for good or for evil.
And don’t get me started on the lack of soundproofing in the sit down loos or the ones that flush as soon as you stand up.