Q for Other Breathwork Nerds- Rickson Gracie and Wim Hof

Hey y'all. I was wondering if anyone else is into Wim Hof breathing exercises, and also if anyone heard Rickson Gracie on the many podcasts he's done over the last couple weeks.
Wim has always generally instructed in his breathwork to bring in a big inhale intentionally, and then to let it go out passively. I just saw Rickson on Rogan, explaining an almost antithetical perspective. He looks at the exhale as the contraction, and the inhale as the solution. He thinks that one can't get a deep, diaphragmatic breath without first expelling to empty.
I've been playing around with this idea, it's interesting... Anyway, lemme know if you have any thoughts on the topic.

"Breathe Motherfucker!#%(*&!!" -Wim