I saw this thread a couple of days ago and went through the whole thread.
It brought to mind a couple of pics of signs I have seen.
The first is a bit of a niche one. If you ever, (or if you have ever) visit(ed) Venice, you will be looking at the street signs a lot as you try and work out where you are,

and most of the time you either see a sign to the Rialto or San Marco, as they are the two biggest tourist traps, but I found a sign where it doesn't seem to matter which way you go, you will get to both.
Now the other one is also Venice, but I'm not sure what they are trying to say,

"ladies beware of men looking over the wall when you are in the toilet",

or "chaps can look over a wall at the ladies in the toilet here".

If it is such a problem that they have gone to the trouble of putting a huge slightly cryptic sign in a glass door, then why not just design your toilet so it is not a problem like everyone else.