Spanking your children

This is a continuation of a poll I saw earlier here. Those of you who don't believe in spanking your children please watch this video. And tell me what would you do in that situation. As you can see, these kids' parents don't believe in spanking either. Personally, I'd slap the rebel out of those kids. But I'm curious, how'd you react to this?
PS: you guys are just saying why you wouldn't hit your kids but not answering the question of WHAT WOULD YOU DO?