Canadian idea, what do you think ?

Remove the price tag that's typically on the shelf below the product. It's usually just a little paper insert behind some plastic.

Little US flag or Trump stickers that you can discretly add to packaging.

Placing the products upside down is a good one.

For loose produce: place fruit or veg in the little carry bags that are usually nearby, as much as you can fit. Then, just put the filled and tied bag back.