I think reverse breathing is one area that needs a big CAUTION sign over it. Something along the lines of DO NOT ATTEMPT ANY REVERSE BREATHING - BEFORE YOU HAVE ACQUIRED THE UNDERSTANDING OF HOW TO MOVE AS A UNIFIED WHOLE DIRECTED BY THE CORE.

And you can get that far with just regular abdominal breathing. Even learning to breath abdominally and have it feel natural is a study in and of itself for a lot of people.

The inexperienced playing around with reverse breathing would be like putting a kid who had no driving experience in a car on a highway in heavy traffic. And, yes, it can be that dangerous.

I never write in all caps, I don't swear that much, and I rarely use exclamation points. But in this case:

DON'T FUCKING DO IT!!!!!!