No (again). No to someone's assertions on the internet regarding how to make a workable filter material.
Testing is required, and I am of the opinion it can be done without "sophisticated equipment and reagents."
Conversely, if it does require special gear, then prove it.
Well, then conduct that testing yourself if you believe that is not hard task for your to test the virus penetration through materials. The stuff used in my home designed filter has been described above. But before you start I would advise you to familiarize yourself with requirements for such kind of procedures.
https://www.astm.org/Standards/F1671.htm Good luck in testing.
Sure, thanks. I consider it very important to actually know what you are doing, instead of relying on guesswork. Looks like other people are looking into it.