It would be nice if the solution to this did not require any effort.

Part of the problem with any automatic thing is that it is more prone to failure. Toilets are so ubiquitous that if something like this were to have an impact, it would need to be close-to-unbreakable.

No this thread got me sitting here thinking about toilets and trying to come up with a design that solves this, and an outhouse comes to mind. <grin>