That stuff really does a kickass job! I cleaned a hood latch assy and 2 hood brackets w/springs. I have a pic of the hood latch after it was coated with zinc chromate.
Believe it or not, White Vinegar will also eat rust. It might take a week or more for heavy rut -- but it really does work and a gallon is $2. I keep a little plastic cottage cheese container full that I toss old bolts, etc in as well as a big pan for larger parts. I use it and then run it through a paint screen before putting it back in the plastic jug for next time. After it has worked its magic I usually wash the part (to get the acid off) and coat with Ospho to prevent any flash rust and to be sure I've neutralized even the rust that you can't see. And... when you are done you can pour it on the weeds in your yard for added value!
