Ok, spanking is a part of a punishment arsenal. You can spank, you can scold, you can withhold, you can threaten, you can yell, you can guilt, and you can explain. There are lots of tools in the parental tool belt. And you should use the correct tool with discretion. Personally I used spanking on points that I needed to make clearly and strongly. When my kid was trying to stuff a paper clip in a light socket. When my kid was running across the street. Those were times when I did not want my kid to test me or get it wrong. And since my kid had never been spanked she really got the message that this was something really bad.
I also, spanked my oldest child because she thought she could hit the rest of the kids. After a bunch of yelling and explaining and sitting on the stairs, we simply smacked the kid like she was smacking her younger siblings. Problem solved and the other kids were very happy.
But, let me warn you. A kid will be able to take a spanking if spanking is used too much. And since its your last card, you are now out of ammo. Good luck. The kid will know he has taken your worst and he will be empowered. So, I advise that you use spanking as a last resort or an explanation mark. To get across the point that something is really wrong.
Also, kids can handle spanking. Its not the worst you can do to your child. Withholding love or respect, belittling them, or guilting them endlessly is likely to have longer lasting negative effects. Punishment is not as effective as positive reinforcement. However, every parent knows. Positive reinforcement does not work all the time with all the children.
Have you watched the video?
Reasonable, good post.