Time to take advantage of power in numbers. Try to find a dozen + people in your area who oppose masking. Agree to shop at the same time every week. Pretend you don't know one another once in the store. I'd love to see the stores reaction when half of the customers (seemingly unassociated with each other) are behaving as though it's pre-covid days.
Or: if confronted, gas light them back. Act as though you have no clue what all this mask nonsense is. Respond in disbelief at how crazy it all sounds and make them explain to you what the heck is going on.