Black Powder = great great fun....
especially on a driven pheasant shoot, drop a few in an appropriate friends bag,
bang bang BOOOOOOOOOOOOOM
To clean I just fire a couple of normal fibre wad cartridges and clean as normal... never had a problem even in a Super.
I know I will get some flack over this, but here are a few guidlines :-
1). make sure your friend has a good sense of humour
2). Is not about to drop dead from heart failure
3). you are a safe distance away from him - in case he chucks a dead pheasant at you.
4). His gun is modern and ok for black powder...i.e. any recent O/U will do!
5). even though BP is OK for virtually any gun, he will not be impressed if they don't know what BP is and he has just had one go off in his vintage Boss!!!!!!!!!!!
Jonty