This begs the question how it was done 150 years ago before people had systems to heat.
I figured maybe Ballistol on a towel, patch, and Q-tip before the dry cycle. I quit using WD-40 on my guns.
First off, Ballistol wasn't invented until 1904, so the "back-in-the-day" users of percussion revolvers weren't using it. However, there were mineral oils and whale oil available, so that's what they used.
I clean my percussion revolvers in plain ol' water, as hot as it comes out of the tap. I don't worry about boiling water - seems like a darned good way to get scalded!
My normal practice is to (on my colt clones, anyway) push out the wedge and remove the barrel and cylinder. I remove the nipples from the cylinder, then drop the barrel, cylinder, and nipples in a pan of hot water.
While the barrel and cylinder soak, I clean the nipples with a patch, then blow through them to dry them off.
Using a patch on a cleaning rod, with a jag that makes the patch fit tightly in the bore, I stand the barrel up so that the muzzle is still immersed in the water. I then pump the patch and rod up and down through the bore - the tight fitting patch works like the leather in an old fashioned piston pump - which flushes the water forcefully in and out. I treat the cylinder the same way.
At this point I dry everything off with a rag, then use a patch soaked in Ballistol to lube the barrel and cylinder bores. I wipe off the frame and the outside of the barrel with a Ballistol-soaked patch, wipe off the excess with a rag, then put everything back together.
I seldom find the action parts inside the frame have gotten dirty enough to require cleaning - I just wipe everything off and oil it.
Substitute generic mineral oil or whale oil for Ballistol, and I bet that's pretty close to how it was done back in the day. No dishwasher or detergent required - water is known, by the way, as the "universal solvent".
Have you ever seen "Lonesome Dove"? One of the early scenes shows one of the characters taking his lever action rifle down to the banks of the Rio Grande and using river water to clean it.