Walmart near me has started using receipt checkers lately and they don’t even really do their job, it’s kind of a gimmick really. They just look at the receipt for a second Don’t even look at your cart, but they stop you every time. It’s just such a waste of my time when I’m in a hurry. I had one person even tell me that it was required by law. No it’s not! There’s no law in the USA that says they have to check your receipt.
Just… Don’t stop? Keep walking. They legally can’t stop you and they know it. It’s a psychological barrier, not a physical or legal barrier. Make direct eye contact, smile, say “No, thanks” and keep walking. It’s worked for me so far.