I have found hypnotherapy very helpful. But you do have to allow the therapist to work. If you are completely resistant to the process, then it is unlikely to be effective. A good hypnotherapist, however, can work with whatever you give her, and gradually help the patient to relax into the therapy.
And the therapy really is relaxing. At the end of the session you feel like you've had a good rest, maybe even a nap.
I've had hypnotherapy several times, one-offs or courses, over the years. There were a couple of occasions when the therapist asked me to do something like address an issue I wasn't ready to address. I simply said "No" and came out of trance. The therapist accepted it and moved on to something else. One time I went straight back into trance, the other time not so well, and we ended up completing the session with me 'awake'. Overall the therapy was still effective.
It's about 10y since I last had a session, but IIRC they generally went something like this:
Comfy chairs in a peaceful room.
Relaxed chat about what you want from the therapy (first session) or about how you've been getting on (subsequent sessions).
Therapist starts talking you into trance. There may be quiet background music of the random, non-repeating sort. Might talk about you visualising a stroll through a place you love or they might suggest a location. Might talk about things that engage your senses. Might take you through a focused muscle relaxation. Might take you through a breathing relaxation.
At some point you might find your eyes shutting quite naturally.
Then you'll just hear the therapist's voice murmuring on, while your thoughts drift. You might respond, or you might not.
Then you will become aware of the therapist's voice again as they bring you out of trance.
You realise you've been resting in the comfy chair and the session is over.
Arrange for next week and say goodbye.
Go out, wondering whether anything has changed, or you've just paid for a nap.
I can't say I ever noticed any immediate changes. I noticed the effect after a couple of sessions, and it increased with the subsequent sessions.
Hope it works for your dd's friend.