no i certainly do not or would ever endorse that sort of punishment totally wrong and abusive there are spankings and there are spankings and that sort where they leave the victim with a bruised bottom and unable to sit down as unacceptable forms of discipline
No, that's typically the point where the police would step in if the child can't sit down in school the next day. When I was a kid I had a friend who was spanked that hard. It ended with him going to be with foster parents. Spanking like that doesn't end well.
The goal ought to be as little pain and risk of injury as possible. Parents long ago would make graphic threats such as " ... until you can't sit down for a week." but they were in my case, fortunately, quite hyperbolic. They did scare me, nonetheless.
Any spanking that is going to work, works by inducing moral reflection on the conduct. The behavior changing effects do not come from intense pain. Other effects do come from intense pain and most, if not all, of them are not constructive. So, the lighter and more symbolic, the better.