I think what many people here are saying is modeling is probably the most important influence on children. We guide our children by setting an example. When children are away from their parent’s sight they can get away with all sorts of bad behavior. I am not talking about illegal acts, I just mean what the Q is asking, obnoxious and rude. If a parent’s only means of controlling their child is punishment; the absence if punishment means that child will be out of control. If the child is controlled by their own sense of right and wrong, they take that with them everywhere.
I think what gets confusing is some very nice respectful people use physical punishment to control their kids and their children in spite of unnecessary physical punishment still turns out to be respectful and in self control, because they still had good modeling in their life. Sometimes it backfires if the corporal punishment is extreme. Still, the modeling was the most important influence in my opinion, and so the physical punishment was unnecessary.
The rod is indeed what the shepherd uses to guide his flock, not to threaten or hit.