The "studies" touted by RGF are either anecdotal or psuedo-science. They are not clinical trials. A clinical trial would be a double-blind study using real people to determine if the product had any health benefits.
It is interesting that none of the studies in the RGF literature or website test their units in real life environments. Assumptions made about the effectiveness of the devices used in actual HVAC systems are invalid when based on tests run in chambers.
It is frustrating for me to see this misuse of science and the lack of critical thinking of those who continue to sell this product.