I have read some of Ron Davis' materials. My grand niece suffers from a severe form of autism and since the age of 2 has been receiving daily instruction from specialists both in her home and at school. Davis' successes have been with higher functioning autistics. He himself explains that his process for drawing out a child with autism is threefold:
Individuation
Identity Development
Social Integration

He states:

"If the person cannot experience some form of orientation, then the Facilitator will not continue to work with that person. Without becoming oriented, the individual cannot experience or develop a sense of "self" as distinct from their environment."