I think those things are just bunk. My friend tried some of those rheumatoid arthritis gloves, and they didn't do a thing for her.
She is really into natural medicine, and so she didn't want to take any of those arthritis drugs that her doctor gave her, so she tried the gloves. Well, they didn't work at all, and she was horribly disappointed. Eventually she ended up having to take the meds from her doctor, which really depressed her.
So although I'm not an expert on the subject or anything, I would say be careful with these things -- I would hate to see other people get disappointed like Daisy did.