I’m pretty sure there’s a ton of fine print that says “results may vary”.
Whenever I see any of this weight-loss machines or diet pill crap hawked on TV, I'm reminded of a Simpson episode when the newscaster (I think) gave a breathless "authoritative" expose on something and at the end a voice came in sotto voce and said "May not be true." It's become a family tradition to say the same after much we see on TV.