I’ve been doing this off and on since I was maybe 10 years old. There is no better ab routine. Try it but be warned; your abs(and ass) are about to be kicked.
If you *must* watch it on youtube here’s that link: https://www.youtube.com/watch?v=g9jBjFTBF3A . The above video embed is a self-hosted invidious instance that doesn’t send tracking information back to Youtube. It’s also ad-free.