They did cite a peer reviewed paper in nature to substantiate the spinny head magnets. I doubt it will save their friend, but it's not total hogwash

The paper was published in Nature *Scientific Reports*, not in Nature. Nature SR is a low-quality journal due to its very limited peer review (SR peer reviews only focus on scientific validity of a submitted paper, rather than its perceived importance, significance, or impact -- ie., they check if you followed proper scientific procedures, but won't check if what you're saying makes sense / fits with the rest of the scientific literature). It's a known dumping ground for papers that aren't good enough to be published in a real scientific journal, and it survives/thrives thanks to its association with the prestigious Nature journal.