Who is going to call that 7th foul on themselves that puts them out of the game? When the mediator calls it, that's going to be an issue.
But I can see how it would make people more careful when they get closer to seven.

You might also have to educate people before each game what is considered a foul, especially charging and blocking fouls. Few people are going to call an offensive foul on themselves.

(Interesting choice of category)