They use it on race horses, I do know that. I think NY State even passed a law allowing it a few years back. Topical, not oral. For years it has been rumored to be an ingredient in WD-40, they deny it, and its not listed in their MSDS, however part of their listed analysis includes "proprietary". There are many stories of folks rubbing down old arthritic dogs with WD-40 and realizing miraculous results that last for weeks if not months. Ditto for people using it on their own hands. Soooo... who knows. Urban legend maybe. Give it a shot, see what happens. Edit: https://www.paulickreport.com/news/the-biz/new-york-rules-changed-allow-topical-dmso-race-day/
It's been around since I started in 1975. I have never used but others who have say it works for joint and soft tissue pain. Some caveats, make sure it's diluted, pure DMSO will blister your skin, whatever is on your skin will get transported into your body via DMSO so make sure the area is very clean. Lastly they experienced a bad DMSO breath. If you try it, report back here.