I have seen it suggested that this would increase the pain of subsequent strokes, though I know of no scientific foundation for this. However there is a very good scientific foundation for what would happen in these circumstances when the young lady had added a powerful electrical device to her knickers, and the consequences could certainly be terminal.
As a general matter of policy, I don’t like naming a school as having used corporal punishment unless I know that it’s a matter of public record. Because of my position, I often have somewhat privileged knowledge of a school’s policies in this area that isn’t in the public domain.