Sorry to be so blunt!
Some male guests rudely pee landing on the rim of the bowl, and leave also drops on the floor in front of the bowl. Besides being gross, it also implies that my place is not clean (the bathroom is shared with another guest room) and i would feel very uncomfortable if i walked in and had to confront this.
How do you dissuade people from doing this? A cute sign? A stern warning in the house rules? What Has worked for you, so that i may use your technique.