I find bathrooms fascinating. I think if I ever went back to grad school I'd do a Sociology PhD on them. For instance, how does one reconcile the existence of the following two bidets in the same culture? The first is precise (one hopes) and discreet almost to the point of paranoia; the other, completely uncontrolled.
This one was in a fancy hotel in Padang. It was hard to get a good photo because I can't angle the flash on my camera. But the idea is, some kind of prong comes out when you press the button. I didn't press the button. I'd only had three hours of sleep and wasn't feeling up to new experiences.
This was on the express ferry back from the Mentawais, and I suspect it was really intended as a continual-flush device, but maybe it was also somebody's idea of a clever two-in-one design. As you can see, there's no opting out here - you get this intense jet of cold seawater rocketing at your bottom, no matter what. It was a weird and slightly disorienting experience, but ultimately not catastrophic.