JAX works great. I guess it depends what you want the outcome to be. I've used the JAX Black on steel and Brown on brass. Colors the steel to a greyish color and the brass to a dirty brass color. JAX Black also blackens solder - which was an added benefit. I use Brakleen on all metal before I solder, brown or color, like with JAX. I've not used anything else. You could do a search here for "antiquing metal" - it's been discussed and the dead horse has been beaten numerous times. A bottle will last for quite a few guns. I don't throw out the solution after it's been used to color metal. I just put it back in the bottle - doesn't seem to affect it.
Good luck,
Kevin
