The owner of the place I go to has an autistic nephew. I was talking to him about DS and he has agreed to meet with the LEA specialist teacher, let her take photos of the place and basically let DS get used to the salon gradually.
What we've been doing until now is taking him on the rounds of every place in the area so that no one poor hairdresser has been traumatised anew by the horror involved in cutting DS' hair 
I know that some people here have had awful experiences with unsympathetic hairdressers too 
Is there a charity or organisation which recognises the efforts people make when they are helpful? If not then there should be. I'm not sure how, maybe in the form of a certificate or credential since it's such a problem for so many families.