I understand your skepticism. But you should start with the orthotropics youtube channel. Obviously, not an unbiased source of information. But it's a start from which you can at least critically evaluate what they say.

Another thing to bear in mind is that scientific theories are obviously developed faster than they can be proven. And as long as what Orthotropics is not invasive you can try what they preach yourself and draw your own conclusions rather than wait for academic silos to try prove that the method works.

I am trying it on myself. The results are not magical, but I can feel them, I can breathe better. And at the end of the day that's what matters most