From what I can tell from my brief viewing of this chapter, this is similar to a technique I use already on my GF.
I pretty much took it from a guy called David Shade (look him up!)... I'll try to describe as best I can without the help of diagrams;
you put your lips around the clit almost creating an air tight seal if you will,
and acting slightly as a support. It's called the big O for 2 reasons if you know what I mean.
Then when you're lips are supporting the surrounding area, let your tongue caress over the clit... or do the alphabet with your tongue continuously... mainly focusing on the key 1oclock position. Every now and again I will take 10-30 seconds and focus on a different area of her vagina... but mostly stay on the clit for around 10 - 30 minutes.
Men, if you attempt this, one of you will eventually get tired and stop. Be proud if you make HER tired first.
This will give her amazing continuous orgasms. Also the good thing with using your mouth is added lubrication isn't necessary