Best thing you can do to get more flexible isn't to read a book or watch a DVD. I'm pretty sure from your other post on this subject that you already KNOW what you need to do to get more flexible. Now it's just a matter of doing it.
There's no magic pill.
I know, but I'm intrigued to see what this method they're on about is on the website.
The method is ages old. It's called "how to seperate someone from their money".
There are no magic pills, and anybody who claims miraculous results is just another flavor of charlatan.
Time and consistent work are the keys.