Hypnotics regression absolutely 100% does not work. You’re creating false memories, which is incredibly easy to do. Human memory is very, very, very fallible. This nonsense is exactly what triggered the satanic panic in the 70s, where there was a sudden proliferation of stories of childhood ritual abuse all coming from this kind of hypnotic regression, and every single one turned out to be complete fabrications from the subjects being hypnotized.
We’re talking about memory recall, not mind control. Memories are fundamentally unreliable and are very easy to influence, intentionally or not.
https://en.m.wikipedia.org/wiki/False_memory