As of late, having been forced to go shopping again, I've made a habit of holding onto things things I don't want till I reach the line. Once there, I'll find a worker and hand it to them directly.
It's a minute kindness, aye. Most people don't know what to do with it at first. However, I reckon that the stockers at these big-box retailers already work hard enough. Might as well make things a bit easier.
At the very least. the girl monitoring self-checkouts seemed quite grateful. She was very kind, thanked me twice. ^~^