At my old boarding school a “double six” twelve stroke caning was very occasionally given as an alternative to expulsion under special extenuating and mitigating circumstances. Our Headmasters canings were so severe that the caning was split up into two doses of six strokes with a recovery period in between. The first dose would be meted out in the morning after chapel and the next dose late that afternoon.
I only experienced four and six stroke canings from our Headmaster and they were excrutiating corrections indeed