For the least of a greasy mess, just load your black powder, then fill over the powder with at least 1/4 inch of corn meal filler. Take care to make sure the corn meal is level and completely more than covers the powder charge. This acts as a fire break to prevent a chain fire from the cylinder's front. Then seat the ball on top of the LEVEL corn meal
without using a lubed wad under the ball
nor grease over the ball.
No grease nor greasy mess at all to have to deal with.
Unfortunately grease mixed with BP fouling makes a mess and will get all over your fingers and hands when you reload and also grabs grains of powder as you reload a chamber and you will wind up with some powder grains NOT in the chamber but stuck to the forcing cone and cylinder face that you will constantly have to wipe off on reloading. If you use that method you will have to carry a rag with you and use it constantly and your rag, revolver and hands will be black grease/fouling sticky and dirty and you will have a greasy handgrip hold too.
I used to use lubed wads and also as an alternative just greased over the ball. But after shooting a few times with just the corn meal as a filler/fire break (to prevent cylinder front chainfires) I never use grease anymore.
Each to their own method, but my way is MUCH cleaner with no greasy mess and no cost for expensive lubed felt wads either. I was always taught and believed that lubed wads and or grease helped soften black powder fouling and kept your cylinder's arbor lubed and longer from binding due to fouling.
But my experience has found the opposite to be the case. Not only was the grease a royal mess but it caught and held the black powder fouling and quickly became a black greasy mess that after a cylinder or two of firing seemed to actually INCREASE the fouling gum up problem on the cylinder arbor shaft. Although my cylinder may sometimes bind up a tad quicker without using grease, it isn't worth the mess to me since I can easily remove my cylinder and wipe off the non greasy fouling from the arbor shaft and be back in business very quickly. With my '58 Remy quick removable cylinder just a few seconds actually. Just a little longer with my Colts.
So yes, I and everyone else shooting BP usually does carry a rag, but with my way, my rag may get a little dirty relatively dry fouling on it from wiping off the arbor shaft to unbind the cylinder after firing a cylinder or two, but at least my rag doesn't get all greasy....and neither do my hands nor my revolver. Much cleaner way to shoot.....in my opinion.
As long as I have cornmeal in my possibles bag, I never use grease. (But I do carry a tin of grease with me just in case I DO run out of cornmeal while shooting, which hasn't ever happened yet).
Plus when you get finished shooting, you can use the corn meal to fry up some corn dodgers or batter your game for the pan
.