KN: I'd like to know what you researched and how involved you were, if you don't mind sharing.
Well, I haven't kept a log of all of my research into this subject, and there are two different areas of research here: the supernatural and the psychology of delusion beliefs.
But ...
In regard to the first subject, there was 30+ years of reading WTBTS propaganda which (among other things) tried to prove the supernatural. Those publications were wholly unsuccessful in achieving their goal; indeed, they only convinced me that God, demons and the angels likely do not exist.
Parallel to that, I read other outside sources which took a scientific approach to debunking the paranormal. Some included Michael Shermer's work through The Skeptics Society as well as the work of James Randi. Frankly, it all gets silly very quickly.
My research into the psychology of delusion beliefs and cult recovery has been much more rigorous and scientific. Click HERE for a short list of articles and other resources which I have consulted on this and closely related subjects.