Civil disobedience.
I wear one going through the door and immediately remove it. I wear it again checking out. No one has accosted me yet.
I have been seen and ignored by employees who appear preoccupied with other things and couldn't care less. I'll ignore them if they accost me; until the manager appears and asks me to leave.
Then they get to re-stock my cartful of merchanidse.
Well, judging from the mounting of a lot of the masks I see on people, it certainly is a waste of time.
Only wear mask in clinic or hospital.