firstly my experience of hand caning at junior school (across the palm) was that the first stroke could dull the pain of the subsequent strokes (excluding the finger tips)if applied hard. A “skilled” caner would progressively increase the severity of strokes and this had the effect of increasing the total pain felt.
At Grammar school the Headmaster could and would vary the intensity of a caning by slipping in one or two strokes across the thighs which were infinitely more painful.