1) There's a big difference between the cleaning we do at an event, known as a "quick and dirty field cleaning", and the more involved cleaning we do at home afterward. The Quick and Dirty method gets the gun ready to fire again for tomorrow's battle, but would ruin it if you left it that way for the next event some months later. The more thorough cleaning is meant to "winterize" the gun for long term storage and non use until next season.
2) A fully "de-farbed" Civil War rifle can cost up to $1200, with even the cheapest ones running about $695. This stuff ain't cheap. Reproductions are costly and this is an expensive hobby. Weapons with brass fittings and wooden stocks are much harder to clean too because acceptable gunpowder solvents like hot water or bore cleaner clean the barrel but eat away at wood finishes and tarnish or rust the brass.
3) Our guns have to last a lifetime. A soldier's gun only had to last until he could replace it with another one picked up off the field or was issued a new one by the US government. Reenactors have to have guns that shoot reliably for twenty, thirty or even forty years. A reenactor's gun is his lifelong friend.
4) It's much harder to clear obstructions from the barrel of a muzzle loader. Try pulling out your ramrod after it gets stuck because you put the wrong kind of brush on it. Almost impossible :P If the powder plug at the bottom gets bad enough the gun may be useless.
5) Loose black powder does cause really bad fouling inside the barrel. It helps to shoot a few live rounds on the range once in a while to clean out the rifle grooves and keep them sharp.
6) During the real Civil War soldiers had to clean their guns a lot less often than we do now. Every cartridge box was issued pre-loaded with at least forty rounds, and of those I think every fifth bullet they shot was known as a Williams "Cleaner Round", that was a bit wider and expanded more when fired, scraping out the barrel as it went. So when they fired live minie balls in combat the muskets were actually self-cleaning.
7) Long muzzle loading rifles are much harder to clean properly. They don't come apart into lots of pieces like an M1 Garand does. Most guys who try to take apart their guns for "cleaning" (and aren't professional 19th century gunsmiths) quickly realize it's almost impossible to put the lock mechanism back together with modern tools. If you want to take apart that percussion hammer and lock "just to see how it works" and try to reassemble it, then you'd better sell tickets-- because you won't get it back together by yourself, and believe me, a lot of people will pay to watch you try!
While we're on the subject, I found an 1896 edition of Harper's Weekly magazine with an article that details proper care of muzzle-loading hunting rifles. Which I will reproduce here. Who better to turn to for advice than people who lived in the 19th century and were the authority on cleaning black powder firearms?
Enjoy and take heed.
THE CARE OF A GUN.
BY H. H. Benson
reproduced from Harper's Round Table. New York, Tuesday, March 3, 1896. Vol. XVII.-No 853.
Aside from the pride and satisfaction which every sportsman should take in keeping his favorite weapon bright and free from spots, inside and out, it pays to keep a gun clean. The residue left in the barrel after firing contains acids, which will soon eat "pits" or spots in the metal, and when once started, it is almost impossible to prevent them increasing in size and number. When badly pitted, the recoil is increased by the roughness in the barrel. A gun can be cleaned by the following directions.
The cleaning-rod should have at least three tools-- a wool swab, a wire scratch-brush, and a wiper to run rags through. Have plenty of water at hand--warm if you have it, if not cold will do nicely [EDITOR'S NOTE: We now know that steaming water just under boiling works best, because it heats and loosens the powder with a solvent effect and also quickly evaporates. Use hot water] Affix the swab on the end of the cleaning-rod, and then some water in a tin basin or wooden pail. By placing one end of the barrel in the water, you can pump it up and down with the suction of the swab. [EDITOR: This sounds interesting. Never thought of doing it that way. Barrel must be removed first of course] When swab becomes discolored take fresh water, squeeze out the swab in it, and repeat the operation, until the water comes from the barrel as clear as it went in. If the gun has stood overnight, or longer, since using, it is best to put on the scratch-brush after the first swabbing, and a few passes with this will remove any hardened powder or leading. The next step is to fill the wiper with woollen or cotton rags, and dry the barrel thoroughly. When one set becomes wet take another, until they come from the barrel perfectly dry.
Then stand the barrel on end on a heated stove, changing it from end to end, taking care that it does not become overheated. By the time it is well warmed-up, the hot air from the stove will have dried out every particle of moisture left in the barrel. If no stove is at hand, the last set of drying rags used must be plied vigorously up and down the barrel until it becomes quite warm from the friction. Drying is the most important part of cleaning, and if the least particle of moisture is left in the barrel it will be a rust spot the next time the gun is taken from its case. The gun may now be oiled, inside and out, with sewing-machine oil or gun grease, which can be had in any gun-store. The woollen rags used for greasing soak up a great deal of oil, and should be dropped into the gun cover for future use. [ED: Note how you throw nothing away after the cleaning, everything is/can/should be recycled]
In regard to the safe handling of guns, almost all rules centre in that of always carrying the gun in such a way that if it should be accidentally discharged it would do no harm. If this rule is borne in mind, and strictly obeyed in the beginning, it becomes a habit, and is followed intuitively. The gun may be carried safely on either shoulder, or in the hollow of either arm, with a sharp upward slant. A breech-loader is so easily unloaded that there is no excuse for getting into a wagon or boat, or going around a house, without unloading. Never hand a loaded gun to anyone who asks to look at it. Whenever you pick up any kind of a gun to examine it, always open the breech and see if it is loaded, and the habit will grow so that you will do this almost without knowing it. It seems needless to say that you never pull a gun toward you by the muzzle through a fence or out of a boat or a wagon, yet the violation of this rule is the cause of more accidents than anything else. Never climb a fence with your gun cocked."
REMEMBER: ALL THE PHEASANTS EVER BRED WILL NOT PAY FOR ONE MAN DEAD.
The article goes on to state rules and common-sense laws about hunting; namely, do not shoot anything that is not on your property without obtaining the property owner's permission first, do not shoot game out of season, and obey all hunting regulations in the area in which you hunt. Also do not go hunting alone if you can help it. Take a friend or a fellow hunter along, or a dog. Most dogs are intelligent enough to find help when an accident occurs.
Also, here is another helpful poem I lifted out of my father's old Boy Scout manual.
A Father's Advice
If a sportsman true you’d be
Listen carefully to me. . .
Never, never let your gun
Pointed be at anyone.
That it may unloaded be
Matters not the least to me.
When a hedge or fence you cross
Though of time it cause a loss
From your gun the cartridge take
For the greater safety’s sake.
If twixt you and neighbouring gun
Bird shall fly or beast may run
Let this maxim ere be thine
“Follow not across the line.”
Stops and beaters oft unseen
Lurk behind some leafy screen.
Calm and steady always be
“Never shoot where you can’t see.”
You may kill or you may miss
But at all times think this:
“All the pheasants ever bred
Won’t repay for one man dead.”
Keep your place and silent be;
Game can hear, and game can see;
Don’t be greedy, better spared
Is a pheasant, than one shared.