It was an informal non RCT study between 2006 and 2007, and the results were never published though Findley has spoken about the study to the Canadian media and the article is still online:
http://www.cbc.ca/news/background/health/lightning-process.html
[...]
Research
"We are dealing with a number of disorders, and we are still not able to divide the subgroups carefully enough — we're looking at apples and oranges and plums," agrees Dr. Leslie Findley, an expert in Parkinson's disease and a clinical neuroscientist in Essex, England.
He is conducting a pilot study with CFS patients and the Lightning Process — the first independent study of its kind — and he says so far, his research indicates it benefits about two-thirds of patients. For the other third, there is no change in their illness, and in a small number of cases there can be bad relapses.
While the findings are not as high as the 100-per-cent success rate some practitioners of the Lightning Process claim, it does imply that the training program can help some people, and that a verbal technique can be used as a treatment for this physical illness.
"Do I believe that CFS is psychosomatic? The answer is an emphatic no. It is a disorder of the brain," Findley says.
But, he adds, he doesn't think the Lightning Process is going to be the definitive treatment for CFS. "Most patients, if properly managed, will recover on their own. I just see this as another way of helping patients that haven't responded to much simpler approaches."