I was roughly around six years old when it happened but certain experience can never be forgotten.
My parents didn't know about this practice either but the uncle assured them that it was something that was going to work. It wasn't in any way a gruesome experience, I just didn't like dancing for thirty minutes. And I mentioned that it was the worst day of my life because I had mumps out of the blue. It was rather sudden and unexpected.
Thank you so much for the link, I'm going to check it out right away.