There are two answers to this question. One depends on acceptance of spiritual principles, and the other depends on scientific evidence that can be replicated.
From a religious and spiritual viewpoint, the soul and the body are linked through physical and mental health. Physical health represents the state of the soul, and if the soul (mind) is stressed or damaged by abuse, the body may change to reflect that stress. Diseases such as cancer are thought of as soul reflections. In this theory, spiritual healing as the alteration of "energy" in the body can improve mental health and so improve physical health. However, since the human body is capable of incredible feats of self-healing (entirely outside of religion or medicine), many anecdotes about spiritual healing cannot be assumed to be entirely from those spiritual effects. Additionally, there are literally hundreds of differing methods, making it difficult to set down a "correct" methodology that can be replicated.
From a scientific standpoint, while the idea of "energy" in the body, as bio-electromagnetic energy, has been conclusively proven to exist, the body can be affected in dozens of ways by any number of outside forces, but only physical changes brought on by specific treatment can be replicated. This means that spiritual healing is unlikely be measurable beyond measurements of the placebo effect, which is well-documented as a link between mental health and physical health. There is no reason to avoid attempts at spiritual healing alongside traditional non-spiritual treatments.
In the end, if the patient wants to experience spiritual healing, it is that patient's choice, although the efficacy of all treatment can only be understood and documented through repetition and success rates.
Since we are living in this world, of course as a human we can't see what actually happening in the spiritual world. Spiritual healing doe exist for those that believe in it. I once heard a story years ago of a women who was demon/spiritually-possessed (I’m pertaining to real life story) who was received spiritual healing. As I’m listening to the story of course I didn't believe, simply because it doesn't exist in my very thinking. But when it came to a point that I saw with my human eyes a same scenario-it was then I started to believe. Spiritual healing will truly manifest to someone who is undergoing a treatment for those that they called "spiritual healer or faith healer. Absolutely it works for those who are eager to receive a healing in their spiritual problem, but traditional medicines could also work, coz we may not really know what is the patient's real problem-he/she may be emotional challenged or psychologically altered. About the charges it all depends upon the agreement of 2 different parties.