Never heard of that but I'll be looking at the link you put in.
I have done NAET with mixed results, but the theory now is that DS is lacking enzymes which has nothing to do with allergies / intolerances so no 'method' can cure him. But funny enough, the NAET guy found DS was reacting to dairy (which we knew), iron (he could not absorb it - proven by blood tests done subsequently with no iron in his blood) and sugars - which I thought was funny and 'out there'. When we saw the GI last week, believe it or not she thinks DS is lacking some enzymes called sucrase and isomaltase which are required to digest sugars. So all in all his findings were quite 'spot on'. I know some people have said there are endless appointments for NAET treatments, for us it was about 5-6 treatments in total.
http://www.naet.com/If you're interested, I think it's best done by a chiro although my guy was a naturopath. There is a link on this site to find a practitioner near you.
Other BWers have recommended to me kinesiology. Near me I could only find Applied Kinesiology which is done by a chiro and that helped a lot. But there are other forms of kinesiology that can be available to you. The chiro who did the AK with M did help him more than the NAET guy TBH. She is great and helped us out loads.
If I recall, your LO is having GI issues since having a stomach bug is that right? I guess you're looking to find out what he's reacting to at this point? What are his symptoms?