You may have heard that using various commercial mouthwashes may help in preventing the spread of the Covid virus. Even rinsing with household bleach has been recommended by certain individuals who shall remain nameless. Hopefully, no one has taken that advice seriously.
Mouthwashes are marketed to reduce the volume of oral bacteria and thereby help in the treatment of gingivitis. As I have written previously, there is a simple solution for treating gingivitis. It is called brushing and flossing. If done properly and effectively, little else is needed. But back to Covid.
There is little to no research to show that commercially available mouthwashes are of any benefit in helping to reduce the spread of the Covid virus. Even if they were effective in killing free-swimming virus in the saliva and oral cavity, the problem is that the virus enters target cells. Once inside the cells, they are protected from the effects of mouthwashes. In addition, the virus populates areas deep in the back of the throat and the lungs (not to mention blood vessels and other vital tissues). Mouthwashes have no ability to reach these areas or tissues.
Hence, until there is more convincing research, even if mouthwashes were able to kill the free-swimming virus, they would have little effect in eliminating the main viral load, and therefore they would have little ability to reduce the transmission of the virus from one person to another. It is the same as using mouthwash to treat gingivitis. They may kill millions of bacteria, but there are billions in our mouth, so the millions they kill is relatively insignificant.
For now, the best ways to reduce the transmission of Covid, or for that matter, the flu and the common cold, remain wearing masks (and possibly face shields), social distancing, and hand sanitizing. Stay safe!