Yes, try Corrosion X. Oshmans carries it. I've had it remove rust that I did not think possible.
That reminds me. I was at a knife show in Chicago last year, and an engraver friend, Ray Cover, Jr., told me of this trick: soak or dab BreakFree CLP on the rust and let it sit for a few days. Then get out
a magnifying glass and you'll see that the rust can just flake off. You can pick it off with tweezers or blow it off with canned air. Rinse and repeat.
It worked for me on a "stainless" knife with a, um, stain on it...
Hayword N. Edgewise