There's no guarantee that the information they received was true. I imagine hypnosis is in the same category as lie detectors with respect to its...interpretability.
I appreciate many think it's snake oil, I did too years ago. But have seen first hand great results.
In the 80s we had Satanic Panic because of false memories "retrieved" with hypnotherapy. It turned out that the "memories" were implanted unknowingly by the hypnotherapists themselves.
I find those ideas intriguing in their own ways, but I'm not sure if they'd help in my situation.
You certainly can get memories back this way; the problem is that they'll be fabricated, especially from childhood.
I agree both these kinds of therapy are effective though.
FBI still works with hypnotherapists.
Have you considered some sort of regression therapy such as hypnotherapy or if more adventurous, plant medicine? I sat next to a pretty senior FBI guy on a domestic US flight once. He was a hypnotherapist who claimed that in almost all cases they were able to use hypnosis to get information about what happened even if the conscious person was completely unable to recall any details.
In most shamanic traditions, a lot of work is devoted to bringing up and purging out past trauma. Examples include plant vapor baths to sweat things out, purgatives to release emotional trauma (often present in the stomach / belly) and plant medicines such as ayahuasca that act as both a purgative and help form new perspectives of past experiences.