I have used evapo-rust for a little while now, and I love it. A friend and RU-vidr had a fire in his shop. About 20 gallons was donated to him because of all the rust from the water used. It took care of all the rust that his shop suffered.
Evapo Rust is a great product, I use it to remove rust from all kinds of reloading dies and tools I've been given. Some cleaning and buffing and those dies will look as good as new.
I’ve seen this product used before and have been amazed by its ability to remove rust. Obviously you wouldn’t, and probably couldn’t, try and reload with rusty dies. But, do you think the tolerances of the dies and mandrill could be greatly effected?