@mystery-ak I put the below on another thread. The reason medical people say don't let the public wear them, is due to people adjusting their mask when out in public. Why they don't tell the public that, is a mystery. The below is what I wrote on another thread.
One has to know the "rules" to wear them so they will be effective. The ones to have are the N95s and if one can find "Face Shields", those, too. When you are ready to leave your house, using your clean hands, place the N95 on your face and clamp down the nose piece until it is tight around your nose. Don't have any space open between the mask and your face. Once leaving the house, DO NOT TOUCH THE MASK AGAIN until you are home again. Do not reach up to adjust it after you leave your house. If wearing glasses, that is some cover over your eyes. If you have a Face Shield, put that on with the mask and nothing is getting in your mouth/nose or eyes.
If you stay 6 ft. away from everyone, you can wear the mask/face shield again. If you are among people, closer than 6 ft., like when you are in a store and checking out with the clerk, that is closer than 6 ft., so when you get home, take the mask strings off your ears and untie strings on the face shield if you have that, and drop the mask and face shield if you have one on, into a plastic bag with straps on it so you can draw up the bag and tie the straps. That goes in the trash right then. Then, do the proper washing of your hands. If you are wearing medical gloves, get rid of them when you get rid of the mask/face shield.
Due to being an EMT, I have a box of N95s, a box of face shields and a box of surgical masks with plastic eye shield attached to the top of the masks. I have given some away to older friends and some to our dog groomer along with giving her some long term food and a big pack of toilet paper. She doesn't have much money and she is a dear friend and my little dog and she love each other.