Hey. I have found a point about that, And I think it's powerful.
It comes from the book "Patterns Of The Hypnotic Techniques of Milton H. Erickson"

“We do believe that when Erickson uses the term unconscious mind he is referring to more than just some term left over from the Freudian foundations of psychology. We believe he is referring partially to the functioning of the dominant cerebral hemisphere that occurs below the level of awarenss, and also to the functioning of the non-dominant cerebral hemisphere. He is probably referring to more than these two aspects of mental processing, but we are sure that his use of this term include these two functions. His overall strategy while conducting trance inductions appears to have these three dimensions:
(1) Pacing and distraction of the dominant(language) hemisphere;
(2) Utilization of the dominant hemisphere; language processing which occurs below the level of awarenss;
(3) Accessing of the non-dominant hemisphere
”

I think the function of "let go of conscious mind", is to shut the "dominant(language) hemisphere", so that the information can go into "non-dominant hemisphere" better.

Yet I still want more scientific research of this.