It's not admissible in a court of law. There is a lot of concern about using hypnosis to "recover memories". If you recall the day care sex abuse cases of the 1980s, there was a lot of hysteria about ritualistic abuse done to numerous kids in several day care centers. This was about suggestability.
The upshot of all this is that suggestions or questions/statements from a therapist or investigator can influence children's recollection and memory. (You can google and find lots of info about this online.)
As far as adult memory retrieval, this is also somewhat controversial. Under hypnosis, you are in a very suggestable state ("When I count to three, you will think you are a chicken"). In using EMDR, the way it was explained when I was trained is that "whatever comes up, comes up. It may be real or not." My sense on memories or images that come up under EMDR is that one should not take them literally or assume because you flashed on an image of your grandmother giving you an enema that you were sexually abused by her.
Blissfully retired after 35 years treating sexual abuse