I second that, Edmonton. I've seen KMK on stage three times, and while there is a lot of fuss made about the spanking, both before and after, not once have I actually witnessed a satisfactory spanking of Kate.
It's possible that the 1953 MGM musical delivers the best Kate spanking of all. Howard Keel spanks Kathryn Grayson at least 22 smacks, and it is played for major effect. Wish the stage performances were that good.