I have been the target of the usual MLM schemes. Amway and Shaklee. There was another one that was extremely popular, Metaluca. Same basic concept.
My deceased JW uncle was always getting involved in MLM, the one I remember that was the strangest was a company called NEMA (amen spelled backward). If I remember correctly, the hook was that everything contained vitamin C. He invested in the company, but I don't think it ever took off.