Well I have not used real black powder for a very long time but when I was a kid my dad always used to make me clean his after shooting with just plain old soap and hot water in the kitchen sink. After everything was cleaned up a light coat of oil was applied and we never had a problem. I had a chance to use and hunt with some tripple7 powder about 7 years ago in a muzzleloader and that stuff was great for cleaning. Again just a patch soaked with water and the gun would be clean after a few patches and never had any rust issues at all.
I have always just cleaned my black powder firearms in hot water and Pinesol. Both cap and ball revolvers, inlines, and traditional muzzle loaders. With the traditional I wipe it down with Thompson Center Bore Butter but for the others I just apply a little bit of oil and have never had a problem. Now when I say hot water I mean boiling hot water. It will get the metal so hot that you have a hard time holding onto it and once the metal is that hot any water that touches it will evaporate quite quickly.
Everyone has different ideas about trophy pictures. Looks around and you will see "long armers," "set behinders," "big cheesers," and "blood covered brutes." I have a few tips to keep your trophy pictures from being laughers or worse yet just plain gross.
#1 Clean it up. Try to avoid bullet holes, gut pile, mass amounts of blood, and the tongue sticking out. You don't want your big buck to look like a angry 1st grader with his tongue out or a MMA fighter during the 3 round.
#2 Long arming...