This product is very similar to that process, it is far different from an instant cold blue process. The metal is prepped to the degree of polish just as in what you know as traditional rust bluing, then boil the metal in plain water to remove any traces of oils. Apply the solution cold from the bottle while the metal is still hot from the boiling water, it will turn a greyish black almost instantly. Coat for as even a color as you can get. Return to the boiling water tank for the specified time, and remove, dry, card, and repeat until you have the depth of color you want. The work that is saved in this procedure is the time saved in hanging the coated barrels to rust at each application. The chemicals are different, a grey black color is obtained very quickly, and deepened with repeat boilings and cardings and applications just as in traditional rust bluing. You would be very surprised to learn the number fo shops that are using this method as their only rust bluing method. It is called an "express" method because of the time saved in hanging to rust. One of the best products is Brownells Dicropan IM, I have used it any number of times with full success and satisfaction.
