If the liner is the only problem you need to find someone that reloads their own ammo. With any luck they will have a vibratory case cleaner. The media is available from the Eastwood Company. Buy enough to fill the tank half full. Remove the bowl from the case cleaner and replace it with a cheap plastic dish. Drill a hole in the center of the dish that the tank can rest on and cover the dish with a rubber pad. I use a couple of mouse pads. Let the tank vibrate for 8hrs and then turn it upside down for another 8hrs. When you dump the media there will be nothing left in the tank.
Like Frisco said the inside will rust fast. After trying most of the stuff on the market there is only one product I will use. Sudco Rustol
www.sudco.com/rustol.html
This will not hurt the paint and is the best product I have found.