The google search "cloth mask efficiency" immediately brings up many links. Here is one from the front page that has a scientific slant for those of you that prefer numbers to opinion.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/
Further to that, a page within that page, showing different visuals of cloth type masks.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185834/