I have an older Browning lightning 20 gauge that is a salt gun.This is the one with the cross screw thru the forearm. Took 3 months to get it out after extensive soaking in every penetrating oil known to mankind. Including KROIL. It had that shiny finish. Since the gun was in rough shape ,I decided to redo and experiment with the salt and finish issue. I used ZINNSER power stripper spray. It took two or there applications but all the finish came off . I found that you have to follow the time directions. leaving it on too long and it had a tendency to dry. I used a plastic body putty applicator and plastic putty knife to scape it off. After I finished I washed in hot water and let dry for several days. For the little tough areas I used a stiff industrial ( Harbor Freight ) plastic type tooth brush. I sanded it after it dried and finished with Tru Oil. I also tried using SALT AWAY, a product I use on my boat and soaked the wood for three days to try and draw out the salt cure. Washed again and soaked in water and let it dry. I actually did that before the refinish part. Before I reassembled, I coated the inside and any wood areas in contact with metal with WEST epoxy thinned 5% with acetone to help flow, I beat this gun up pretty bad when I hunted, so I was not afraid of hurting it. I also found a used stock for $1200, but I was not about to invest in a restock. I derusted the areas and cold blued the parts , used moly lube on the internals and it is back together and looks pretty good. How long the metal/wood stays this way is yet to be determined. USE RUBBER GLOVES.
sorry this is so long but I hope that it helps
Rich K- chemist