Also generaic citric acid (the above are gelled citric acid) if you can soak it. Citric acid without gelling doesnt have enough dwell time.Spotless Stainless. Also CitriSurf 2310 Gel. I have used both with essentially equal results. Both work best with surface temps above 75 degrees. The CitriSurf 2310 Gel is avaialble from The Rust Store. It is much less expensive than Spotless Stainless but it is available in gallons.