Most books on witchcraft will tell you that witches work naked. This is because most books on witchcraft are written by men. - Good Omens, Terry Pratchett and Neil Gaiman
Masks, molecules, COVID-19, and their relative size
If a mask blocks carbon dioxide, it will be fantastic against COVID-19. And a mask doesn't have to be able to block individual viruses to reduce transmission.
The Daedalnexus 