Are there any rules in the military that prohibit Multi Level Marketing?

Yes, entering into private business or financial deals counts as fraternization.

Lots of wives do that sort of thing in housing. It's gets crazy stupid with all the Pampered Chef parties and Mary Kay cosmetics. But you can't do it at work.

Look guy. I've seen this time and again over 26 years. Knuckleheads and their goddamn get rich quick pyramid schemes. And even worse trying to foist their BS on their buddies

If you want to become a pariah and the butt of jokes just go ahead and get involved in your pyramid scheme BS

well if you plan on a get-rich scheme on the backs of your battle buddies, count on a short career. you can't run it out of the dorms, and it isn't supposed to be run out of base housing either, but it is not widely enforce.