When I am King...
Airplane bathrooms will always be clean.
There are two irrefutable facts in life: everyone prefers a clean bathroom and is generally tidy when they perform their ablutions, and the bathroom on an airplane looks like the remains of a frat party the morning after "free grain alcohol and beef jerky night" at the local liquor store.
Since everyone is a model of toilet fastidiousness, how does that tiny room become such a hellhole after a few business travelers have gone in there to take care of business?
If you're the first person, you're set. FAA regulations may be somewhat lax on things like de-icing wings and avoiding rivet-shaking turbulence (which the pilots apparently think is more fun than riding a rollercoaster, though the sick hordes in coach beg to differ). But they're absolutely rock-solid on two things: the bathrooms should be tidy on takeoff, and nobody should have a container of toothpaste in their carry-on that holds more than the amount needed to cover a single bristle.
But if you're the second or later person to use the bathroom, good luck. You're better off holding it until you land, rent a car, and drive to the nearest gas station with a rest room that hasn't been cleaned since the Eisenhower administration (now there was a presidency that believed in bathroom cleanliness). If you can't wait that long, then you just tiptoe carefully into the airplane bathroom, close your eyes, and let fly. Which, come to think of it, probably explains the mess.
When I am King, there will be accountability for airplane bathroom mess. There will be a Toilet Monitor official on the plane (I nominate the Air Marshall, who hopefully has nothing better to do for the duration of the flight). After each person leaves that little closet of personal space, they must wait while the bathroom is inspected and approved for further usage. If the bathroom fails inspection, the former occupant is responsible for cleaning up the mess they made. Think of it like cleaning up after your dog when he goes on the pavement. Only this time it's you, and there's no plastic bag available.
Only through such means can we expect everyone to do their part when they part with their doo.