I could tell you many a tale about slippering and boys I had caned in my office, but do not want to go into all the details as I may be accused of taking over this good site.
I recall one mother about 1955 complaining about two boys who had thrown mud at her washing. She gave me their names. In those days we could deal with offences outside school. I sent for the two boys and they admitted the offence. I told them they each get three strokes on their backsides.
I then invited this mother, not of the boys, who was sitting down to leave. She made no effort to move. I said in the end to her that it would be better if she left as I was the cane was always used on a bare bottom.