Re: Odd fouling problem
To remove this very tough fouling, just get some lead away clothes. This stuff does a number on baked on fouling and lead deposits. Will take off bluing so be careful. Simple.
I too have tried Butch's bore shine and was unimpressed. Did ok with the powder fouling. Certainly no better then hoppes or other cheaper products. I use GM top engine cleaner too.
On copper, it was horrid. Simply did not do the job. If shooting match barrels where copper fouling is very low, would probably be just fine. For everything else, I rate it dead last.