I use blueing as well, browning isn't a process that I would use on anything on a mustang. It looks like old rust.
After bluing, I rinse them off in hot water and baking soda, blow them off with compressed air. At that point I put them in a zip lock back and spray them down with Sheath. It's an oil in a spray can that also works as a desiccant.
I soak the entire quantity in the bag, push the air out and zip the bag shut and usually leave them for a few days. Sometimes I use the tumbler I used for my brass cases when I reload with an agressive agent to strip bolts, other times I will glass bead them, spray them with brake cleaner and dry them with air, then I put an entire container of Permablue in a dish dip them and lay them on a paper plate, to allow them to process. They are cleaned and use the same process as above with the gun sheath.
This very closely resembles phosphate. You have to be careful about using a fine wire wheel, then bluing. If you do, often they wind up a bright iridescent blue instead of the black-blue from the other processes.
-Keith
