Its like a number of words, the same combination of words can have many different meanings, the generally accepted meaning of the word is parody. But just look at the context of the word on the page. I would think the information on the page makes it clear that the meaning here is intended to be quite different.
I don't disagree with that. It's different because it's intended as a product ad parody, so the product isn't "parody" itself. Parody is not a substance, liquid, or chemical, but "Spoof" is. We differ only in the interpretation of what the product is. Whatever the product is, it's green in color. It says so right in the text, even though the page itself is not in color:
"My friends have begun to comment on my distinctive appearance. They haven't many friends who are green with a full coat of Spoof." Coating yourself with Spoof makes you turn green. That much evidence doesn't tell me what Spoof is, but it's enough data to tell me what it's not.
You're insisting way too hard on trying to make sense out of nonsense. There is no hidden meaning, no dirty joke that you're expecting to find. They spent all their ammo on the front cover. It's "not really very funny", just like Crash said.
So you've got one clever sight gag based on a bawdy off-color euphemism (the front cover), one gross-out potty-humor gag (the back cover), and the rest of the pages filled with attempted satirical humor that completely misses the mark, and isn't worth the time taken to read them. Fairly typical of the many attempts by comic publishers to cash in on the success of MAD, without really attempting to understand the Mad approach to humor and without the talent to compete with it -- which is why none of the MAD comic book knock-offs lasted. What can you expect from Charlton?
Any editor worth his salt in the business knew that the cover was the most important page of the book. Unfortunately, some of them thought it was the ONLY important page of the book. Don't assume that any of the other pages were written by the same dirty mind that came up with the cover gag. That's why they paid more for covers than for interior pages.
To my way of thinking this isn't much different than a run-of-the-mill example of an Archie Comics publication of the 1970s (the ones not written by Frank Doyle or George Gladir or Samm Schwartz, because Archie had a dozen spinoff titles with pages to fill). Often there was a well-drawn (by Dan DeCarlo), humorous gag on the cover, but when you read the stories inside, they were all junk. Nothing that even slightly compared with the cover -- if you were lucky you might get one 6-page story that was worth your time. Too late, you already paid your money after you saw the cover.
