The Big 45 Frontier Metal Cleaner pad is far better than a tornado brush. Just cut off a piece of it, wrap around a bronze brush, and it’ll clean better than anything else. And it WILL NOT damage the bore! I spin my rod in an electric drill and run it back and forth. There will be NO lead or plastic remaining when finished. Only takes a minute or so in a drill. Pay special attention to the forcing cone and choke areas. And also it is great removing light rust from bluing without hurting blue.

https://www.big45metalcleaner.com/

When an old man dies a library burns to the ground. (Old African proverb)