Uggh, the research as far as you and I know is complete. There has been no one that has been able to confirm one more instance where it was effective nor one instance where it was not.As I already said, any further research will be yours to do. You posted a statement as fact that didn't seem right...I researched and found what I thought you'd read...and asked for your cite. You provided the cite, and your author didn't say or claim anything close to what you stated. He used four stories that were, by his own words easy to come up with, and was completely factual about the results. Your own source disputes your statement. There is no debate.
You can certainly try, and if you succeed I will gladly say I was wrong, until then nope. If you can find four instances where it wasn't successful then we can debate as to its merits.
Esse quam videri