Sounds like pseudoscience to me
(, Wed 30 Jan 2019, 1:15, Reply)
Given that there's usually very little non-oxygenated haemoglobin in your blood, but there are conditions that can cause low blood oxygen. I suspect there is an element of placebo effect here - if I'd gone to all that effort I could probably convince myself it made me feel better!
(, Wed 30 Jan 2019, 7:38, Reply)
after converting your kitchen sink to a deep diving pool.
(, Wed 30 Jan 2019, 8:19, Reply)