Astral Projection with the Mantra S.

The Mantra S

The disciple must enter into a slumber state while vocalizing the letter S like a still, small hiss: Sssssssssssssssssssss.

By vocalizing the letter S, the student will acquire the capacity to resound the still, small voice within his brain, the Anahat sound at will; this will allow him to consciously project himself in his Astral Body.

Can I get some clarification on this?

I can achieve this high pitch sound with either vowel I or S when relaxed. But just being able to hear the sound does not facilitate astral projection. If it was that simple I should be able to project every night or whenever I wanted by merely relaxing.

1. You've relaxed. You're body is in the numb & fuzzy state.
2. You start internally vocalizing the vowel S (or I), either from before reaching a relaxed state or afterwards.
3. You hear the high pitch sound in your head.
4. ????
5. You project.

What is number 4?