It works ok...about like any rust remover or rust converter. The main thing to remember is there is no magic product out there. The secondary thing to keep in mind is you have to be able to clean off whatever you've applied. With some products that isn't so easy. A few years ago the hot answer was to use molasses to remove rust. But it turns out that isn't quite the miracle all these people on the internet said it was. And some say baking soda, but I haven't tried that. One guy around here for a while was saying to soak the rusted parts in water. I figured he was kidding or possibly crazy.
You can use phosphoric acid and neutralize it with soda and then just wash off the remaining residue. And you can use very strong vinegar (25% or so), but you need to be careful with any acid not to leave it on too long and be certain to neutralize it at the end of your work. I've heard some say oxalic acid or citric acid and a product named CLR can also be helpful. Just remember to neutralize it.
Good luck!
