Here's something I just briefly looked up
Effectiveness of Cloth Masks for Protection Against Severe Acute Respiratory Syndrome Coronavirus 2
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Cloth masks have been used in healthcare and community settings to protect the wearer from respiratory infections. The use of cloth masks during the coronavirus disease (COVID-19) pandemic is under debate.
The filtration effectiveness of cloth masks is generally lower than that of medical masks and respirators; however, cloth masks may provide some protection if well designed and used correctly.
Multilayer cloth masks, designed to fit around the face and made of water-resistant fabric with a high number of threads and finer weave, may provide reasonable protection.
Until a cloth mask design is proven to be equally effective as a medical or N95 mask, wearing cloth masks should not be mandated for healthcare workers. In community settings, however, cloth masks may be used to prevent community spread of infections by sick or asymptomatically infected persons, and the public should be educated about their correct use.
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The key points.... cloth masks provide "some" protection and has not been proven to be equally effective as medical and N95 masks... that and wearing a cloth mask should not be mandated for healthcare workers.
It's too much to read the whole thing in one setting, but masks do have their place.