Just the word "breathwork" is obnoxious to me. I suppose it's interesting that if you hyperventilate enough you can reduce oxygen in your brain to the point where you hallucinate. And that is probably safer than taking psychedelics.

But the idea that you would do that routinely seems obviously stupid to me. I think if you keep doing it for a number of years then you could damage your brain. My understanding is that your brain needs oxygen.