My first Headmaster when I became a teacher wrote me a memo explaining what he expected of me with regards to the use of the cane, along with a copy of the school’s regulations on corporal punishment, and that contained a bit of advice on how to do it. But I didn’t really practice. When I had cause to use it, I used it, and over time I got better at using it.
We have a bit more respect for the boy’s privacy today, but even today it’s hardly unheard of to see a pupil naked. They still do sport. They still need to change and shower. And they still need to be supervised. And you can’t do that with your eyes shut. There’s looking and then there’s looking, of course