Wear a Mask and fill a cart and walk up to the cash then walk out and leave the full cart
Especially with meats and ice cream and milk and other perishables that will keep the mask-zealots-in-training too busy to hassle and make demands of the customers. Yeah, I know the mask zealots "are just following orders" and I'm a b@stard -- probably a lot worse in the eyes of mask enthusiasts -- for suggesting it, but having a little "fun" with the mask zealots seems a better response than arguing with them ... it's a milder form of protest which, come to think of it, is even better than wearing a mask as protestors are proven to be immune from the virus germs.