He can be given a cue not to remember when the therapist makes a certain motion or says a certain word that he will go back into the hypnotic state but still keep his eyes open.
"A Practical Guide to Self-Hypnosis"
Melvin Powers
Incidentally, all the hypnosis theories presented are equally applicable to self-hypnosis except where, as in transference, it is obvious a therapist is needed.
"A Practical Guide to Self-Hypnosis"
Melvin Powers
Any good therapist could have done the same for you, and much more rapidly.
"Legacy"
James H Schmitz