First off, my son is verbal and his sensory disturbances are mainly visual and auditory. His tactile senses are faulty in that they are slow and minimal. He has apraxia (though undiagnosed) and I think an underlying seizure disorder (also undiagnosed) as he can sit and zone out regardless of input and will require a strong input to 'reboot' from time to time.
His disorder manifests that he can absorb and comprehend, though demonstrating his comprehension must be done by communication through performing rather than communication via language. That means standardized testing can only measure his "IQ" at just below 70 labeling him retarded. But my son can cook, do laundry, make new friends (recent), perform many tasks which were deemed unthinkable upon his diagnosis.
Whatever helps people to become communicative and function markedly better than the alternative? Worth it. In this case the boy has proven to be educable, communicative, reachable. If rapid prompting can map synapses and give him purpose, great.
I wonder about the concreteness of the autistic brain and its expectation for constant stimuli and using this method to approach real life. What the reality may be is someone will have to be with the boy constantly and do nothing but prompt him all the time.
I suppose we'll see in the future if this proves to be a long-term, lifelong improvement or not.