Here in the UK we can use masks or face coverings. A scarf is acceptable and of course, it can be washed frequently.

Personally, I don't use anything. May be inconsiderate but what about my health? About ten years ago, had a very bad upper respiratory infection. Every few weeks I get a build up of mucus in my throat, which I then have to get rid of. The worst thing I can do is keep it trapped, but I do release it at home.

Also recently found out from a pharmacist that masks trap bugs, germs, etc and they are drawn back into your lungs after you sneeze or cough. If you are forced to wear one, why not try making it then you can control size, type of fabric?