coronavirus in less than 30 seconds, according to a new study.In research led by the Cardiff University, scientists discovered "promising signs" from the preliminary results.The laboratory findings showed that Covid-19 can be killed by mouthwash in less than half a minute.This comes ahead of a clinical trial into over-the-counter mouthwash and whether it has the potential to reduce levels of Covid-19 in a patient's saliva.Scientists found mouthwashes which contain at least 0.07% cetypyridinium chloride (CPC) have the potential to combat the bug.The report - The Virucidal Efficacy of Oral Rinse Components Against SARS-CoV-2 In Vitro - is yet to be peer reviewed but supports another study published last week that found CPC-based mouthwashes.