Semi-related FYI- there are a few natural things that have proven efficacy in slightly shortening the duration of rhinovirus (common cold). Obviously, oral/nasal zinzinc. But also, umckasides (advocated by Dr. Eades) and elderberry, and a couple other things as well. That being said, I try to review a cross-section of randomized trials of alternative medicines a couple times a year, and most of the evidence is for intermediate biomarkers, not health outcomes. In addition, trial quality from studies in the 1990's and before is very poor.
I am very interested to see if anyone (Guyenet? Sisson? Harris? Cordain?) will write a post speculating on the role of natural medicines in paleo times. Obviously we can't know for sure, but I wonder if some medicine wasn't needed as often because of lack of chronic disease (big duh), but acute poultice-type thingies were made for acute disease/cuts/bruises/etc. Biodiversity and awareness of local foliage was likely way way way higher at the time.