I did, a couple of years ago, along the Rhine.
Pulled in when the reception was already closed. I followed the instructions to set up and since the evening was so nice day down at the Riverside restaurant to eat a fabulous meal.
Tried to pay for the spot at the restaurant, but they said to pay for the food & beers then, and the spot in the morning.
Next morning I was up early & ready to leave but reception was still not open. So I left.

Last month I was cycling by the same campsite again & stopped off to pay my tab. The face of the lady behind the counter was priceless!

I'm aware of many cyclists who deliberately try to avoid paying. It annoys me no end.