Is there any scientific/clinical study that shows efficacy and safety of this alternative? I couldn't find any.
I doubt it. I also highly doubt there will ever be any, as there's just no payoff for a company or business to do this kind of research. It's a sad thing that research into low-cost, low-risk therapies are never researched, though it's understandable. I myself think such research into any number of modalities (such as all different kinds of oxygenation therapies that are routinely used in Europe) could lead to dramatically reduced national health care costs, as well as removing much of the risks associated with conventional medical care.
I myself have tried a number of these low-cost, low-risk alternative therapies, and have gotten far better results than I've been able to get from most of the convetional medicine I've tried. I would love to see health care companies and practitioners paid more on the basis of what they can prevent, than what their costs are from performing often very expensive procedures. I think this approach could easily reduce health care costs by 50% or more--and take a big chunk out of our national deficit.
Just one example of a therapy I tried (there are many): I learned about a technique called Nasal Specific (expanding a balloon in the sinuses to open collapsed or restricted sinuses). A local chiropractor did it for $50, and it proved to be a
really significant therapy for me. Just a few years ago, conventional medicine essentially took this same procedure (mostly for people with severe allergies), and turned it into a several thousand dollar procedure, with full anesthesia, and more, and all the associated risks of these kinds of measures.
I myself didn't have allergies, but a friend of mine told me she had the same technique done when she was 19, and her severe life-long allergies completely cleared up and never came back. I suspect that many on this forum who have various kinds of sinus issues (including infections), and other kinds of Eustachian Tube dysfunction could benefit from doing this simple technique, even including possibly having their tinnitus and/or hyperacusis improved.