I had a neighbor that was Mexican when I was a kid and the parents did use diaper punishment on their kids.
My neighbor had an 8 year old Mexican boy that would wear diapers for punishment and his mom would also make him drink from a bottle and would change his diapers right outside on the front porch.
She also had him in a playpen and I was talking to him one day at the time and he said he was being diaper punished for getting into trouble.
He didn't say what he got into trouble for but he just said he got into trouble and was being diaper punished.
He didn't say directly but he seemed to like being in diapers and being treated as a baby.
I'm not sure if it's common but diaper punishment does really happen in real life.