Soul healing or spiritual healing has different meaning to everybody. My most important rule with this approach is to respect client's spiritual beliefs. Also, respect clients not having any spiritual beliefs. My approach does not ask you to believe in any religion or new age spirituality, like chakras, or Angels or anything else. And if you do believe, this is good too.
For me the soul healing is learning how to access the core of our being, the deepest feeling of real unconditional love, to yourself and to others, and all what comes together with that, the wisdom, compassion, acceptance, gratitude, trust, peace, joy. There are no more powerful techniques to use at this level as just soul talking to the soul, love awaking love, joy and peace bringing joy and peace.
However, there is a method which works on this level, the level of love and acceptance, and I use it, sometimes in hypnosis as hypnotherapy and sometimes in a group workshop. This method is called Family Constellations or Systemic Therapy. Family Contellatios work allows to release the destructive patterns in family systems and to restore the natural flow of love.
You may also consider exploring the deepest knowledge of your soul, memories of your life as a soul, between incarnations. This is called spiritual regression, or "Life Between Lives" hypnotherapy, founded by Dr. Michael Newton. However, I do not offer spiritual regression as a part of hypnotherapy process to treat psychological issues. I strongly believe that the earthy issues need to be solved here and now, on earth, and once this is done you are more free and more open to explore your spirituality.
How this could be related to the fear of frogs in our hypnotherapy example? Sometimes the fear of frogs is just a top of iceberg; Mary may have lots of other fears and she may want to address them together. Or after overcoming the fear of frogs she may realize that she wants to continue to grow. The truth is that the transformation on the deepest level of your soul, when you are more clear about purpose and meaning of your life, when you can see the reality from the wider perspective, the fears simply drop. There are no limits to what can be achieved.