The Arthritis Cure may well be a long shot pipe dream. Till then, simple measures like wax bath and splinting can make a huge difference.
Rheumatologists straddle the space between musculoskeletal medicine and immunology, but we are generally more inclined towards biochemistry and physiology than we are to physics and engineering, owing to our undergraduate curriculum. As such, we have a conceptual bias against conditions and therapies which are more mechanical or physics oriented. We can pretty much wrap our brains around chemical equations, and imagine antibodies and cytokines hitting on cells, but our eyes glaze over at the mention of electromagnetic waves or piezoelectric forces. (Orthopods and Radiologists, on the other hand, are more at home with this.)
So papers like this are typically met with much cynicism, perceived as bordering on homeopathy and the metaphysical. It's an unfamiliarity bias.
Rules-of-thumb for supplements:
1) The effect size is small. Otherwise the big pharmas would have gone bust eons ago;
2) The response time is slow. If you're better by the next day (or week even), it's definitely not the supplement. Either that, or it contains steroids and/or analgesics;
3) As long as it is safe and affordable, try for 3 months. If it doesn't "kick in" significantly by then, cut loss and move on.