J.U.
I had a neigbhor once that we would allow the kids to come over and play without mom/dad visiting. We (the moms) had decided we didn't see anything wrong the kids just by themselves coming over and knocking on the door to play. With that said when her daughter would break a rule--even if it was something I knew she mother didn't allow or if it was one of my rules--I would simply tell her she had to either follow the rules or go home. More often than not she chose to go home. That was that. If I was watching all of the kids and there was no one home then we all move the play outside away from everything. No real punishment just would relocate them to a more neutral area.