I have started the online intensive course I mentioned in the OP. There are five parts and I finished part one today. It is basically HG's voice following along with presentation slides. It was about two hours long.
I like the theory behind the approach. I think it really makes a lot of sense. I just wish the language wasn't so - fluffy. Not sure if that is the word I am looking for but all the talk of "energy flow" and "inner greatness" and "juicy relationships" seems to detract from program's credibility.
I still plan to use the approach. I might just tell my more critical/skeptical husband about it and only have him watch specific portions.
As for using it at school, that ended up working itself out. Our OT went to the meeting to address sensory accommodations and she brought up NHA as well. Her son goes there too, she uses this approach (kept up with the credit system the entire school year) so his teachers were already familiar with it. My son's teacher was not familiar with it specifically but she knows the OT's son had been having behavior issues which have drastically improved. She seemed really mellow so I don't think she would be one to energize his negativity anyway.