Any item I found interesting in a comic book ad were things available in the retail market, such as Aurora model kits (run in many of Marvel/Curtis magazines from the early 70s), Mego action figures, etc. I do remember ordering novels from Warren's Captain Company, which allowed me to pick up titles that had long been out of print.

I think my dad did growing up, but I wanted to send away for Wizard/ToyFare exclusive things SOOOO badly growing up but never did sadly! My parents never wanted to pay shipping for things and they'd sometimes throw away the papers to mail away by accident(I think it was an accident). I'm making up for it now by purchasing a lot of the exclusive things from these magazines and comics. But ALWAYS wanted to at the time.

Most of those were simple little pamphlets, maybe with a few basic moves diagrammed, then come-ons to part with more money.  You see mention of "books, supplies and equipment, which you could purchase through martial arts vendors or in dojos, in addition to signing up and paying for lessons.

There is one issue of Deadly Hands of Kung Fu that features an article about a martial arts tournament and exhibition, in which his school and some students participated.  They were making @$$holes of themselves and generally irritating people, but didn't impress anyone within any competition portions.  The real guy was John Keehan, from Chicago, born into money and influence.  The hair was because he worked as a hairdresser, as well as a martial arts instructor.  He had been involved in the USKA and broke away and tried to promote a rival group.  He and his school were involved in an incident where they invaded and started fights at a rival school, leading to arrests and trial, where he was acquitted of anything pre-meditated, but the judge scolded everyone involved and gave notice that a repeat would end in a stiff sentence.  He was also alleged to have been involved in a major robbery and was questioned by a grand jury.  He died in 1975, of internal bleeding, related to an ulcer, at the age of 36.

It was just an update of ages old cons in pulp magazines and comic books (and men's magazines) appealing to the gullible and people of low self esteem, who thought they could fast-track their way to skill, popularity or success.  He just used more language of martial arts films, which were booming, at the time.  Sol Brodsky's son, Gary, who started the short-lived Solson Comics (publisher's of such fine fair as Reagan's Raiders and Sultry Teenage Super Foxes) also sold crap to losers, blaming feminists and other women for their failures and secrets of sexual power and success and other BS.

By all accounts, John Keehan was certifiably nuts, as much as a con man.  Others, like Frank Dux, of Bloodsport fame, were just frauds and con men, snowing gullible Hollywood producers and Bruce Lee-wannabes into buying their crap.  Guys like Ashida Kim (Radford William Davis), George Dillman, Steven Seagal and anyone else claiming to teach dim mak and the power of chi/qi as some overwhelming force.

About the only legitimate martial arts pieces in comics were the technique illustrations that Frank McLaughlin did in Judomaster and Deadly Hands of Kung Fu.  McLaughlin was a legit judo black belt and teacher, aside from being a comic book artist and inker.  Larry Hama also illustrated some real stuff, in an Iron Fist story or two..  Paul Gulacy studied Bruce Lee movies and replicated techniques from them.  Kirby included actual judo and hand-to-hand techniques taught in the Army, in Sgt Fury and Captain America.  Just about everyone else drew generic kicks and chops.  Marvel filled deadly hands of Kung Fu with movie reviews and articles, some accounts of tournaments and exhibitions, some book reviews and some outright BS, from people who knew diddly-squat and couldn't even be bothered to read an issue of Black Belt magazine to even fake it.

The whole Black Dragon Society thing was taken from the movie serial, G-Men vs The Black Dragon, plus a real "society" of Japanese immigrants who maintained political ties to Japan, but were never really spies or saboteurs.  There was an earlier version, who provided an espionage network, during the Russo-Japan war, at the dawn of the 20th Century.  By the 20s and 30s, it was just a conservative political movement, which backed the militarists.

Sweet Tooth Jones was more legit.

The only things I ever sent away for were several catalogues for back issues (including Robert Bell, mentioned above). The only one that piqued my interest thanks to an amazing selection and really low prices, was Lone Star's (today better known as mycomicshop.com). For about a year or so starting in the spring of 1981, I ended up buying quite a haul of back issues from them.
Otherwise, though, no I was never tempted to get X-ray specs or sea monkeys or toy soldiers, nor lured by the prospect of making a fortune by selling Grit.

A neighbor friend and I pooled our resources and bought one of these:




We had a lot of fun with it. I saw them still available somewhere just a few years back, and I wish I had bought one!