Used the bronze brush & elbow grease method & have successfully removed the fouling.
Will try some of the alternatives next time. Thanks for the advice.

In reply to Tac. cast lead balls / bullets. melted, cleaned & cast from some very old Lead recovered from a bay window roof.
My ROA has a nitro cylinder so I use 4 grains Unique behind 0.457 ball or the Lee ROA bullet.

Al.