I am an experienced and qualified Hypnotherapist. While I work primarily as a Counsellor, I do sometimes use Hypnotherapy and Guided Visualization to support this work.
It can sometimes be the case that there are emotional blockages from the past that can’t be accessed adequately through conscious discussion. Being able to dip down below the level of everyday conscious thought, language, behaviour and defensives can be very valuable.
I believe the best example of this is inner child work. Whereby, you would be guided into a relaxed state and a meeting of your younger self is facilitated. There are various ways in which this can be done but in essence it can provide a chance to heal and provide your younger self with what they need. For some, this meeting and connection to a younger self can provide a more tangible and healing experience than solely verbally exploring childhood.
Where appropriate, individual recordings can be made of these sessions so that you can continue the work between sessions. Having a resource like this can also support your continuing growth once counselling has ended.
My professional body the British Society for Clinical Hypnosis (BSCH) has some useful information on Hypnotherapy here.