A rash of provocative headlines this week offered a tantalizing idea: that mouthwash can “inactivate” coronaviruses and help curb their spread. The stories sprang from a new study that found that a coronavirus that causes common colds — not the one that causes Covid-19 — could be incapacitated in a laboratory when doused with mouthwash. The study’s authors concluded that the products they tested “may provide an additional level of protection against” the new coronavirus. To read the full story.