It’s not about cleaning the fiber and fabric, etc. It’s about improper handling of the masks during washing, drying and the following steps will contaminate the entire mask, especially the side directly touching your nose and mouth. That’s why they are one-time use only.
Even trained health care professional mishandle their equipment. In our labs, with strict rules, extensive training and sophisticated decontamination equipment, we get bacterial contamination every once in a while. Civilians are simply not equipped to correctly decontaminate anything. The simple thing is to avoid complex handling, thus one-time use.
