Closest reference I could find to this important question - Conducted on SARS in 2003. Showed that oven at 75 degrees for 30 minutes made SARS non-infectious. Didn't find similar study on Covid 19.
Biomed Environ Sci.
Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation.
Viruses stayed stable at 4 degrees C, at room temperature (20 degrees C) and at 37 degrees C for at least 2 h without remarkable change in the infectious ability in cells, but were converted to be non-infectious after 90-, 60- and 30-min exposure at 56 degrees C, at 67 degrees C and at 75 degrees C, respectively
The survival ability of SARS coronavirus in human specimens and in environments seems to be relatively strong. Heating and UV irradiation can efficiently eliminate the viral infectivity.
Furthermore, N-95 masks were shown to stand the repeated stress of baking.
From Stanford, also referenced in the quote from Live Science the quote (where Gary's misquote appeared).
Can N95 facial masks be used after disinfection? And for how many times?
"With respect to the hot air (75 °C, 30 min, 20 cycles), we found that an N95 mask did not suffer any mechanical deformation and the ear straps retained proper elasticity required for use."" 1) Hot air applied over 20 cycles did not degrade the filtration efficiency (>95%)."
75 degrees Centigrade, is 167 degrees Fahrenheit - my oven will go as low as 175, close enough. I'm going to bake my only mask at 175 degrees for 30 minutes every now and then.
Todd Swanson, MD, MPH