Simple answer to your question is no, it doesn't work. There are no studies using scientific rigors have been able to prove anything apart from retention increasing during alpha wave state...a relaxation state. Acquisition and Processing of Information During States of REM Sleep and Slow-Wave Sleep, and Perception Without Awareness of What Is Perceived, Learning Without Awareness of What Is Learned, etc.
That being said, your mileage may vary. You may have good or bad luck. We all have different learning styles, and maximizing the learning experience is something you need to discover about yourself as you learn. If you discover that your are a sleep-learner and that it works for you, your ideal methode for retention will depend a lot on paying attention to which methods work FOR YOU.
I believe that relaxation is the key...getting yourself to a place where you're free from distractions, calm, relaxed, and focused...will stimulate alpha waves and lead to better retention. How much better? That all depends on how your mind works...there are no "right" answers. Pay attention to your mind-state and physical environment when you read a chapter and think to yourself, "Wow! I get it!" That place may be in bed for you as you frisft off to sleep. It may be lunchtime. It may be an afternoon nap. You won't know until you experiment.
I agree with @DaveNewton that whatever you do will take more than one session. There is no magic bullet to learning. It's a matter of reading the material and solidifying that experience by whatever method you find necessary - flashcards, notes, highlighting - to recall the material.