It is very logical for everyone to wear masks while out in public right now. If you have a fabric mask, what is the best way to keep it clean? Popular Science listed some good ways to keep your fabric masks sanitized.
You can boil your mask for 5 minutes. It seems harsh but it gets the job done. If you go this route, it is recommended that you only do it 10 times and then move on to another mask.
Washing your mask on hot in the washing machine works well too. Handwashing with soap and water is good as well.
You could also leave your mask in a solution of 1 quart of hot water and 1 teaspoon of bleach for 5 minutes. Be careful if you do this. PopSci says too much bleach could damage the mask. You also want the mask to be free of any bleach when you put it on to prevent you from inhaling the fumes. That can be damaging to your respiratory system.