There's actually some sense behind that since one of the places that the virus can get into your body is through the mouth and throat. However by drinking water (or rinsing your mouth) you are essentially removing any viruses that may have been in your mouth.
@Bochulaz oh, I said one? I mean ALMOST EVERY FUCKING ONE USE MASK LIKE THAT. Goddamnit do they also put their dick out when they wearing underwear!? ffs...
@Iheart I kinda have doubts on its efficacy tbh.. I don't think it's that easy to rinse out something that microscopic? And, last I read, the attack site for SARS-CoV-2 is present in the GI tract too, so drinking it down probably won't help either.. Of course, obligatory disclaimer, I ain't a medical practitioner, just something I thought & read before.. Stay safe people.