After leaving a metal toolbox on the floor of a cabin that later got wet and left a large rust stain, I purchased some "THE WORKS" cleaner ($1.19 for 24 ounces) at WalMart. It is basically Hydrochloric acid. Removes rust and calcium stains from fiberglass without damage.
While trying to remove some rust from a deck fitted stanchion, stainless steel, I swiped it at the pitted rust that always comes on such deck fittings and it evaporated the rust. It was WAY too easy. Previously my wife had been using Nev'r Dull, with good success, but hours of work and rubbing.
I wiped the "The Works" solution on, rust gone, and then wiped off the stainless with a diesel coated rag to put some oil on the steel as well as remove excess acid. So far it seems to keep the steel clean LONGER than the Nev'r Dull, and at about 1/10th the time, and 1/5th the cost of the Nev'r Dull seems too good to be true. We're stocking more before WalMart finds out it is being used on BOATS which will jack the cost up like everything else related to boats.
Break Out Another Thousand.... oh well.
STILL never had this much fun even at the BEST day at the office!