Strange sign- Poop Quiz

While travelling northwards, We made a pit stop at a camping site near Piteå. On one of the doors to the common service house was this sign.

What do you think it means? My guess was "Do not throw a handgrenade into the paper basket while taking a dump. And... Errr, being a blob kinda thingy, and with errr, Mickey Mouse ears sort of sticking out of your sternum and back."

Somebody actually got paid for this?

Somebody actually got paid for this!

The right answer is in the comment section...