The preliminary result comes ahead of a clinical trial into whether using over-the-counter mouthwash could to reduce the levels of Covid-19 in a patient's saliva.
Dr Nick Claydon, a specialist periodontologist, said he believed mouthwash can become an important addition to fighting coronavirus along with "handwashing, physical distancing and wearing masks, both now and in the future".
Researchers note that while this is promising for looking at ways to potentially reduce harm by people carrying the virus, there's no evidence yet that the findings (provided they check out in clinical trials) will tell them more about treating respiratory symptoms of COVID-19.
The study has yet to undergo peer review, but scientists called it a "promising" sign that mouthwash could help slow the spread of Covid-19.
The results come after another study also found CPC-based mouthwashes to be effective in reducing viral load, reports BBC.
Though it has not yet been tested in actual humans who have the virus, and the study has yet to be peer-reviewed, researchers who led the study said that the findings are pushing forward emerging research about the prospect of mouthwash as an effective tool to kill off the SARS-CoV-2 coronavirus (COVID-19), and other related coronaviruses.
"This study adds to the emerging literature that several commonly-available mouthwashes created to fight gum disease can also inactivate the SARS-CoV-2 coronavirus (and other related coronaviruses) when tested in the laboratory under conditions that are created to mimic the oral/nasal cavity in a test tube", said lead author of the study Dr Richard Stanton, as quoted by BBC. It has now been submitted for publication in a journal.
"People should continue to follow the preventive measures issued by the United Kingdom government, including washing hands frequently and maintaining social distance".
Results from a clinical trial at the University Hospital of Wales are expected next year.
Researchers noted the clinical trial will not produce evidence of how to prevent transmission between patients using mouthwash.