A word of caution concerning H2O2. As good as responsible usage can be, H2O2 (Hydrogen-Peroxid) does oxidize and as such, it creates free radicals.
What I'd recommend any O2 therapy believer should try is a product made in the U.S. called Vitamin O. Vitamin O has a distinction of not only raising blood O2 levels, but it has made claim to a medical first. While it oxygenates (it doesn't oxyidize), VO raises the CO2 discharge. This makes VO very safe and effective.
The product is double blind studied and after much political battling, it is now legal for the producer to make the medical claim that VO raises blood O2 levels and also raises CO2 discharge ..... a very important feature.