No I am afraid that the Spencer Spanking Plan is a hoax
Then I've been cruelly deceived all these years! I first heard about this thing in the 1970's I'm sure. I saw what appeared to be "news" articles about it, no doubt from disreputable publications. But there is an actual document, hoax or not, that has been around for 40 years or so. What is probably the urban legend is that it was promulgated by a legitimate psychologist as a serious aid to marital harmony.