The real trick is to address the issue after each range trip. Don't wait until after several trips when it has "caked up" and aged.
Whatever happened to using a bit of Hoppes and a toothbrush?
Makes the toothbrush taste funny?
Unless it touches the forcing cone. It's a permanent decoration. You can soak it in Hoppes #8. Other then that, mechanically you can't remove it without rubbing through or scratching the blue. If it was stainless, Flizt metal polish takes it right off.
I wouldn't worry about it unless it starts to touch the cone.