Our work with elite athletes serves as the proving grounds for our methods. Most people don’t play professional sports. But if our methods help athletes at the highest levels, they can work for anyone.
Ido Portal has some content out there about hanging. He often issues monthly challenges to his training community, and one of the summer months was a hanging challenge. During that time he put out a bunch of videos showing different hanging techniques, including both a passive hang (which is probably close to what’s recommended in your book) and an active hang (closer to what the ideal active position by mwod standards would be).
I don’t know how much information is out there regarding how to implement and progress hanging, but there is enough video footage on his YouTube channel and discussion on his blog that you should be able to piece something useful together.