Surface rust removal test: Evapo-Rust

Need to remove the rust from inside a motorcycle tank and I heard good things about a product called "Evapo-Rust". Figured I'd test it first. I rusted a steel 6" x 6" plate by spraying it with salt water and then leaving it outside for a couple weeks. Then I dipped it into the miracle fluid for 2 hours. Looks like it might work!

Ok, so here are to sliding rods from my 1950s drill press. They both had about identical rust. I soaked one for two hours, then rinsed it in water and dried it off. Pretty good!