osteoarthritis and pure magnesium oil spray?

[Adlon57]

I am 63 years of age, and have osteoarthritis, passed down female line. I am affected in my knees, about 4 months ago, after a particularly bad session, after a shower, which I have every morning, I looked in my medicine cabinet, and found an old bottle of pure magnesium oil spray, it did NOT say anything about taking for osteoarthritis, but I sprayed it on my wet knees, dried myself, except for knees. Some relief for rest of the day, I did this routine again, realising that I would have to change my trousers a bit more often, but there has been a distinct relief in my knees! I stopped this routine for a week, and towards the end of the week my old pain symptoms started to return! So returned to the magnesium oil treatment and lo and behold relief! I have noticed my hands are getting clamy, a side effect? Could this be useful in treatment of this medical condition?