I got X-Ray Spex. I'll just say that 12 year old me was disappointed and leave it at that.
Sea-Monkeys and X-Ray Spex: Collecting the Bizarre Stuff Sold in the Back of Comic Books.

Artist and historian Kirk Demarais set out to buy all the stuff he saw advertised in comic books when he was a kid. He wrote a book on what you really got for your money. Much of it was junk, some wasn't.

The Polaris Nuclear Sub looked exciting in the ad, but in reality (as seen in the 1967 snapshot below), it was "a glorified cardboard box, that could be destroyed by anything remotely wet, even dewy grass."

I got the Bag Full of Laughs and the hovercraft when I was a kid. They weren't ripoffs, like a lot of the junk in comic book ads. They worked as advertised, but they were disappointing.

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