Steel wool was my plan, although I have a high speed bench grinder.
Make sure to degrease your steel wool. I keep several pads soaking in a jar of acetone at all times. If you get to the point when you're doing this more frequently, I agree that mounting a wire wheel to a grinder is not a good idea. I use a Brownell's four row fine wheel which I mounted on a spindle made from a threaded bolt. Initially, I mounted it on my large drill press, turning at a fairly slow speed. Now, I use it in my variable-speed corded drill. I made a simple jig to hold the barrels. I find it easier to control the speed, angle, and pressure on the barrels that way. It also enables me to reverse the direction often to keep the wires from bending. I also lightly dress the sides of the wheel with a file card after each set to keep the wires straight.
To card areas like the rib-barrel joint I use the steel wool and a shaped craft stick to get into the joint, just be careful you don't overdo it and leave streaks. Don't forget to wear gloves, but I'm sure you know that.
Good luck, prep and degreasing are the key
