I bought 6 antique pocket watch movements at the Zürich Sunday flea market about a month ago. One of which still had it’s casing which was completely covered in rust (see picture to the left). I bought it with intentions of making a necklace out of it. I realized that rust stains really well and will ruin my shirts so figured I should try to get it off.
Thanks to google, I found out that alka-seltzer will take off rust so I soaked the whole thing in it for a few days and used an old toothbrush to scrub it off. It all came off beautifully (pic on right). It unfortunately tarnished the brass movement inside, but if I can figure out how to get the movement out I can polish that back up no problem. Oh and bonus, now that the rust is gone the gears wind. So I may even be able to get the thing to run again!