A study at Cardiff University has examined the possible use of mouthwash in battling SARS-CoV-2. Researchers pointed to a number of studies including one in 2017 which found a 30-second solution of 34% ethanol prevented viral replication of a coronavirus.
However commercially available mouthwashes are 14-27% ethanol and there is lack of research on the impact of repeated mouthwash use on throat inflammation and tissue integrity.
Manufacturers do not claim mouthwash helps against coronavirus, and more research is needed. Editors note: More research unlikely unless Bill Gates is invested in a mouthwash company.
The World Health Organization currently recommends 60-70% alcohol based gels (at the time of the study) to damage the lipid envelope of the coronavirus on surfaces and hands, which is toxic if ingested.
Note the above is only information from the study and not considered health advice. Consult your doctor.