There are a few cloth masks in this data set showing around 50% filtration of test particles smaller than Sars-Cov-2: https://docs.google.com/spreadsheets/d/1M

There are a few cloth masks in this data set showing around 50% filtration of test particles smaller than Sars-Cov-2: https://docs.google.com/spreadsheets/d/1M0mdNLpTWEGcluK6hh5LjjcFixwmOG853Ff45d3O-L0/edit https://docs.google.com/spreadsheets/d/1M0mdNLpTWEGcluK6hh5L... N95s and similar are obviously better but cloth masks do ok. Also remember they changed guidance to recommend cloth+surgical masks, which everyone laughed at. Lo and behold that combination tests in the 80% filtration range. So cloth masks work, the guidance for double masking was valid, and the N95 recommendations more valid still.