I've swatted my sons ass twice and I regret it. It was nothing that would hurt him but when a parent resorts to hitting a child, it means you lost control and you're falling back on some primal ignorant shit. I believe that teaching kids to fear the punishment only teaches them to try and push the limits rather than learning respect or an understanding of the rules they break. My older brother is a fuckup, got his ass whooped all the time too. He's been in and out of prison. He makes his moves based on what the penalty will be. I don't think you can beat logic and reasoning into someone.
With my son, kickin his ass is a last LAST resort. I'll talk till my face turns blue, I'll give him every scenario I can think of as to why certain shit is the way it is. When he ask me somethin and I tell him no, I give him an explanation as to why I said no so he doesnt just think I'm bein an asshole. I never got that. If I EVER asked my mom "why" after she just told me no I'd get "Because I said so!!" often times with a viscous smack to the head region resulting in deafness...ringing and pain.
But yea, if he chooses to fuck up after I gave him all the tools to do right, then...and only then will we have a problem.