I am not a grounder at all - yet. I still have 2 more soon to be teens to raise.
When I was growing up and I watched my girlfriends get 'grounded' for some odd reason, I remembered then, I will never do that to my own children, b/c I noticed how ineffective it was. The parents are pissed, they say they're going to take this, that or the other away, and then the mean ones follow through on 2-3 weeks of tortuous solitude or give in. Either way the kids learned that their parents weren't going to follow through on their threats, or they were lonely and unforgiven for just too long. I believe children are way smarter than we give them credit.
I'm a get mad in the moment, tell them what went wrong, what we're going to to do in the future to make this not happen again and go to your room so I can have a moment to regain my composure and come out when you can offer a sincere, heartfelt sorry. Then we kiss and make up.
I just remember seeing how ticked off over time my friends became towards their parents and how much they learned to lie to them to avoid these ridiculous and ineffective means of punishments.
And I want to add, I have the most well mannered, sweet, sympathetic, kind, loving kids around. I am complemented ALL the time on their behavior at other's homes, at school events, in public places. It is a pleasure taking being with them.