As a teenager, I once said the f-word in my mom's presence. I got my mouth slapped. That is the only time I remember her ever physically disciplining me in any form. I was more shocked than anything and I promise you I never did that again.
Overall I was a really good kid and didn't get in trouble often. While my parents were still married (divorced when I was 13), my dad did all the spanking, but it was always just angry outbursts, not genuine discipline and he would use whatever was handy. So I think there is a really clear distinction between discipline and abuse. That was why my parents divorced actually, because my dad was abusive to my mom as well. When I was 19 he apologized to me for all that he had done and time has proven that he genuinely repented of it and is a changed man. My parents had a lot of stress and struggles and my dad didn't handle it well. He grew up the same and never learned how to better deal with his anger.
We do spank our kids, and when done right you really don't have to do it very often. We've got a strip of wood, about the length of a ruler, but a little thicker and it has the words "foolishness remover" on it. It was my husband's parent's when he was little. He didn't get spanked a lot really (even if he might have needed it), but did bury it in the yard once. His dad found it and dug it up. He also tried to scratch the words off, lol. We keep it above the kitchen door. We don't like spankings any more than the kids do, but I can't abide a mean or disrespectful child. If the kids get spanked for something, they get ample forewarning and we always follow the same routine. They are informed that the spanking is coming. We allow about 10 minutes or so for everyone to calm down and think about it. We go upstairs and have a long talk about what they did and why it was wrong, spank, then hug it out. This system has worked really well for us.