Hey Willem,Thanks Hydro,,i keep the book in mind and go and listen to the interview,,,
If you get your hands on a copy of his book, he dedicates about 5 - 6 pages on Open G tuning. I have the hard-cover version of the book, and it starts near the bottom of page 241 (don't know about paperback . . . . but the hard-cover has 564 pages with the index, so you can probably find it easily with this information). There are some interesting reveals there that I won't spoil for you here. But, watch out! There's also a lot of sex, drugs, and rock & roll . . . . . . . something for everyone.
Enjoy,
Hydroman52