I missed this thread the first time around though I find it interesting now because I've recently finished listening to the audio of Jed McKenna's Spiritual Enlightenment: The Damndest Thing. He says that enlightenment is the result of an endeavour similar to the what the Initiation of the Dead seems to be.
In summary Jed describes enlightenment as the state that you exist in once you've stripped away everything that is not true. He says that to get there you must first have a burning desire to discover what of reality is truly real. And then go through a process of eliminating everything else. He describes it as a brutal, violent process. It's a very nihilistic approach.
I started reading his second book, Spiritually Incorrect Enlightenment, but quickly got bored because it revealed nothing new, and pretty much was all about how Moby Dick is about his interpretation of the path to enlightenment.
It doesn't sound all that appealing, and Jed makes that point too, as well as the point Gary made, that the experience is just as it was described, but not as you previously understood it to be.
The Initiation of the Dead sounds like it would require far more dedication, passion and belief than most would feel for such an endeavour. A case of normal distribution where the majority of people would benefit more from the slower, step-by-step process, leaving the more dramatic process for the few.