Baking in an oven at 70°C for at least 30 minutes. Household ovens are notoriously imprecise. Measure the actual temperature, if possible.
Make sure your mask is wrapped in some heat-resistant material to avoid spreading contamination. For example paper bag or aluminium foil.
If you have several masks/respirators, mark them to make sure you are re-using them equally – to maintain the best filtration effect on all.
Wash with a detergent at 60°C or more
Always treat masks as contaminated, make sure you clean your oven after using it for cleaning masks! Follow guides on correct mask-wearing techniques!
Crowd-sourced article on various methods
N95 Respirator Reuse Primer
The new coronavirus is sensitive to heat. It can effectively inactivate the new coronavirus by heating for 30 minutes at 56 degrees Celsius. Therefore, the single dry heat sterilization (70 degrees Celsius heating for 30 minutes) can effectively inactivate the virus without affecting the protective function of the mask.
Dry heat disinfection (heating at 70 ℃ for 30 minutes) had the least effect on damaging the filtering mechanism, and the filtering effect could be maintained above 95%.
Can disposable masks be reused after sterilization?
Viral inactivation by heat treatment at 60°C required 15 to 30 minutes to inactivate the SARS-CoV.
Evaluation of Inactivation Methods for Severe Acute Respiratory Syndrome Coronavirus in Noncellular Blood Products - PubMed
Specifically, coronaviruses are thermolabile, which means that they are susceptible to normal cooking temperatures (70°C).