At the beginning of the pandemic, I read about UVC light and purchased a UVC light bulb before they ran out online. I used it to sterilize my N95 masks which were impossible to find, and all the research I did showed that you could do this 20+ times without affecting air flow or filtration of the mask. I even found studies that talked about how to use it to disinfect flu virus so I used those as a guideline as to how long I should expose the masks. I even went so far as to buy ajar and tested that the UVC light at least killed bacteria as advertised. I know viruses are much tinier and there's no way to test for the virus but at least I knew it was working as advertised for bacteria.

Of course all this ended up being useless, but it was a fun project during the pandemic.