Keep in mind that only an N95 (or higher) respirator properly fitted to your face so it is sealed protects the wearer.

All this other stuff covering the mouth and nose: surgical masks, bandanas, scarves, plastic bags, ... does not protect the wearer, but rather are intended to try to protect other people in the area.

There are those wondering about the consequences of people walking through secured area (banks, courthouses, airports,...) with masks.

I need to invent a toothpaste that reacts to dangerous communicable diseases and displays as bright orange when you spit it out each morning. I think I'll do that this afternoon.