Recovering memories
This is easy and exceptionally difficult. The problem is that in hypnosis elicitation (recovery of memories in this case) are very close to installation (making the subject imagine that false memories are real). Here I'm talking about recovering memory for the client - not forensic hypnosis where there are many more rules to be observed and safeguards needed if the recovered memory is to be acceptable to the court.
However, forgetting about the issue of admissibility in court the challenge of recovering correct memories are the same. It is extremely important not to lead your client in any way. But, you are dealing with an extremely suggestible subject and the unconscious may pick up the slightest clues from your word choice, voice tonality, voice tempo, voice volume and other unconscious changes in your sensory output to the person in trance.
The way to recover memory (real or imagined) is to give a suggestion like:
"In a moment I am going to count down from three to one at the count of one I want you to remain in a deep trance with your body totally still while your head remain in trance but you will be able to talk.... three, remaining in the trance, two, totally in control, and one you can talk..."
Now or before depending on the need you regress the subject to the time she wants to remember and ask her to describe the scene. I have used this method successfully to help a client find his passport that he had mislaid.
If I was to try to recover charged memory I would give the suggestion to do it dissociated (that is to say, "See yourself in the image as though you ware watching a movie of the event). Even so I would be ready in case the client associated into the memory and abreacted.
Note: if there is any chance the recovery may need to be sent to litigation you must be trained as a forensic hypnotherapist or refer your client to some one who is thus trained. You will save yourself and your client plenty of bother.
Milton H. Erickson wrote in his "Experiencing Hypnosis:"
"The use of ideomotor signaling in conjunction with the indirect forms of hypnotic suggestion provides the therapist with a creative array of approaches to facilitating hypnotic phenomena and working with unconscious material. In his 1960 paper on the removal of resistance to hypnosis, for example, Cheek provided an excellent illustration of the use of the Chevreul pendulum with questions and the implied directive to help a subject recover a traumatic memory."
I'll later write about ideomotor signaling and the Chevreul pendulum. For now they are ways for the unconscious to communicate with the conscious through micro-movement of the muscles. In ideomotor signaling typically a specific finger movement is selected to signal yes and another for no. Although you can use eyelids or any movement of the body. The Chevreul pendulum is the use of a pendulum which moves in one direction to signal yes and in another for no.