Previously dismissed as a myth, new research now suggests that mouthwashes may help in preventing the spread of Covid-19.
Here's the theory behind it.
In a recent study this month, researchers found that with similar strains of viruses encased in a fatty (lipid) membrane just like the coronavirus, certain agents in mouthwashes were able to destroy this membrane and inactivate the virus in the mouth and throat.
Chemicals that can destroy this lipid membrane include ethanol, povidone-iodine and cetylpyridinium.
"What we don't know yet is whether existing mouthwashes are active against the lipid membrane of SARS-CoV-2," said researcher and lead author Professor Valerie O'Donnell, co-director of Cardiff University's Systems Immunity Research Institute.
“In test-tube experiments and limited clinical studies, some mouthwashes contain enough of known virucidal ingredients to effectively target lipids in similar enveloped viruses,” she said.
O'Donnell and other scientists have called for more urgent research to determine if the simple oral hygiene product could have the potential to reduce the transmission of the coronavirus, especially in the early stages of the infection.
However, the World Health Organisation had earlier stated that gargling with mouthwash will not kill the Covid-19 virus and has yet to change its stance.
Other academics also pointed out that the coronavirus doesn't just reside in the mouth, and gargling mouthwash is not sufficient to eradicate the virus in the lungs, for example.
There's also the issue of toxicity, as frequent use of mouthwashes could cause inflammation in the mouth and throat, which O'Donnell warned as well.
Even mouthwash companies like Listerine have advised consumers against using their product as a way of fighting Covid-19.
So until more research is done, the best thing we can do to curb the transmission of the virus is still to practise good hand hygiene, follow social distancing measures and keep those masks on while out. Oh, and maybe try to talk less loudly if you can.