In the spirit of appropriate technology and route 1 common sense, it would seem to me the best way to handle CoVid is not to let it get a good hold. At heart, it is effectively a souped up cold that can get extra nasty if it gets in too deep, so hitting it quick and early in the nose and throat makes sense to me. Some ideas and reasoning in the two links. This is not advice, just information. Use it as you will.

https://www.georgekramermd.com/hydrogen-peroxide-gargling-nasal-rinses-may-prevent-viral-infection/

https://www.researchgate.net/publication/340433132_Hypertonic_saline_nasal_irrigation_and_gargling_should_be_considered_as_a_treatment_option_for_COVID-19