Another wonderful article, thanks for sharing it all. I have a jar of file but have not used it much - maybe I will have to give it a try again soon.
Your article reminded me of another article I read on the toxicity of sassafras vs. the basic alcoholic beer everyone enjoys so much. I tried to find it but could not, so here is what I remember. As you noted, it takes a lot of sassafras tea or drink to have much effect. A comparison of sassafras vs. the beer found almost everywhere showed the beer to be much more toxic. So why is sassafras considered bad but beer not? No sassafras lobby to keep the sassafras industry going was the basic conclusion! I think it was Dr. James Duke that did some of the research and also has a book on edible plants.
I have a lot sassafras growing in the woods around my house and have shared its scent with my son often. One day I may have to make some tea for him as well.