Based on mental and physical training methods used to prepare flyers for combat in World War II – techniques that were until recently locked under the heading “classified information” – this step-by-step relaxation program has had amazing results.
This is a mild version of what's claimed in the book, which essentially states that he developed a method to teach Navy pilots to fall asleep in 2-minutes flat, in any pose, while their position is being shelled.
The book itself is a waste of time and has two useful pages which describe the actual "techniques", as described in this article. (Tl;dr: "Relax your muscles and clear your mind."). Everything else is useless filler.
Is there any reason to believe that the army did develop a way to train soldiers to fall asleep in adverse conditions, and if so, was it ever classified?