I take my Ortliebs off my bike put hem in the store trolly empty put the food in the grocery trolley too ,

but not in the bags ... put the empty bag 1st on the belt

grocery checker fills them at the register, & I put them, full, in the trolley and return to the Bike Rack.

Put them back on , and ride home. They're Back rollers, so dry inside, empty or full ..