For those of you that have read his book, David D clearly says, DO NOT MEMORIZE THESE LINES. YOU SHOULD COME UP WITH YOUR OWN MATERIAL!
That being said, he's just giving you an idea of what ****y funny is. There's no other way to explain it without giving examples.
Some of his lines are pretty funny, but never does he say use these lines and you will get laid. His ****y funny is just a variation of confidence. thats all. he also recommends saying the unexpected, because that shows confidence too.
I personally find the book ok. It definitely gives you an idea of how to display confidence in a different way. This is definitely not a magic bullet to get girls, lol! in fact C/F mostly works with guys that are below average with girls, whether it be in looks or social skills (hint: david D comes pretty close to fitting this type).
WARNING: Any guy that is good looking or has charm that appears ****y is just a huge turn off for girls. I'm talking from experience here. DYD was the first book that opened my eyes when I was an AFC. I consider myself decent looking and whenever i said anything c/f it turned girls off.
My point being, there are better ways to display confidence. C/F sounds like your bragging about yourself and comes off too conceited for me. Like i said, C/F is for guys who lack confidence, but if you already have it, don't be too C/F!!
Lastly, use this book as a tool to give you an idea of how to seperate yourself from the crowd. Understand how to display confidence, what not to say, what sounds AFC to girls, etc. Instead Come up with your own way to display confidence. there are infinite ways to do that.