How To Quickly Sterilize Non-Washable Masks According To CDC And WHO

Elevate in a covered dish above (not in) ~2 oz of water (no dry heat).[1]
Microwave to a boil. (Over 133 degrees F is really all that's needed.[2])
Let it sit a minute or so. Take it out and let air dry.

1. https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/decontamination-reuse-respirators.html
2. https://www.who.int/csr/sars/survival_2003_05_04/en/