Listerine.
There was a Dr. Semmelweis, Hungarian I think, who noticed a link between babies and mothers with midwives living longer than babies and mothers from surgeons. Of course back then surgeons would do autopsies and then immediately go deliver w/o washing their hands. This doctor was laughed and eventually lost his job.
Lister deserves a lot of credit in that he was accepted. However it should be noted that what Lister proposed was something Ignaz Semmelweis had come upon several year before:
“...Semmelweis proposed the practice of washing hands with chlorinated lime solutions in 1847 while working in Vienna General Hospital’s First Obstetrical Clinic, where doctors’ wards had three times the mortality of midwives’ wards.[5] He published a book of his findings in Etiology, Concept and Prophylaxis of Childbed Fever.
Despite various publications of results where hand washing reduced mortality to below 1%, Semmelweis’s observations conflicted with the established scientific and medical opinions of the time and his ideas were rejected by the medical community. Semmelweis could offer no acceptable scientific explanation for his findings, and some doctors were offended at the suggestion that they should wash their hands. Semmelweis’s practice earned widespread acceptance only years after his death, when Louis Pasteur confirmed the germ theory and Joseph Lister, acting on the French microbiologist’s research, practiced and operated, using hygienic methods, with great success.”