My first caning was three strokes on my hand and that hurt a lot more than when I got it on my bum.
The cane on my (and your) hand hurt more than the cane on my (and your bum) so, which hurt more? The cane or the cane?
The caning I got for the boob flashing incident was a joke but it was still “the cane” and, therefore, considered a serious punishment. Most slipperings were worse than that so, with only that example, I would have to say the slipper hurt more than the cane. With wider experience of both the cane and the slipper, I found the main difference was who was using it and why. Some slipperings were more severe than others – even from the same teacher.