I used horse liniment (DMSO) for years, when I pitched fast pitch softball. Still have some in cabinet. Worked really well, the nano second it touches your skin it permeates and taste like smoked oysters.
At my age I’m starting to believe that what is snake oil to one person is another person’s miracle cure. I too tried DMSO years ago because so many people raved about it. It didn’t do a thing for me but leave a (literal) bad taste. Opiates don’t touch me in any way, shape or form other than to constipate me horribly. But other people love them to the point of addiction. Invermectin may be snake oil…..or maybe it actually works for some percentage of the population. Let ‘em try it and let them live with the results. This ‘murrica after all…..we have the right to be as stupid as we want to be. All you have to do is look at Texas……..