Ahh memories, had the split sixes multiple times in high school (a cane with strands split so they pinched your skinon impact 6 times) was pretty harsh.
Despite that, the worst was a 5th grade teacher who on the first day of the school year proceeded to tell the class what he would and wouldn't tolerate, he pulled out his cane, stacked 3 x 1 inch books on top of one another at hand height on his desk and let rip.
He had a reputation not to cross him at all cost, he opened the last page of the bottom book to show it was folded and crinkled from impact.
The class shat themselves, took me 3 days before I got my first of many many cainings that year.
He still remains my favourite teacher haha.