Yeah. Personally I would have mixed half a gallon of One Restore to half a gallon of water in a pump up sprayer and saturated the area and allowed dwell time. Over the course of several minutes you should see a noticeable difference. You may need to reapply some more One Restore, maybe even at a slightly higher concentration, to completely lift the rust stains. Then rinse with light pressure from a garden hose.
You would probably be looking at 15-20 dollars worth of One Restore at the most and maybe 30 minutes of time.
I always keep One Restore on the truck because it's so versatile. It will clean so many things and has a rock solid reputation. I also keep Rust Remover Plus, but it's a bit more expensive and more focused in it's abilities to rust stains, so I keep it for the really nasty rust stains. F9 works good too, especially on battery acid stains, but that's very limited here, so I only order it on a "as needed" bases so it's always fresh when I need it.