Ralph,
Except for the folks doing some sort of blank firing engagement, where their smokepole gets really really fouled..., a quart of water with a single drop of liquid dishwashing soap works just fine.
The tiny bit of soap reduces surface tension, so the water gets absorbed in less time by the fouling.
Folks have used generic windshield washer fluid..., or some have splurged and used Windex..., or there's a combination of alcohol,hydrogen peroxide, and Murphy's Oil Soap..., and while some might be very good because they have a "base" pH, it's not really necessary unless you have around 30-40 rounds from your gun without having swabbed between shots.
So the reenactors tried lots of combinations, and compared these with hot and with cold water...., not enough advantage was gained (if any) over plain, cold water, so the cost is thought to be unnecessary.
Hot water was touted for generations as it was intended to dry faster, and to help "melt" any greasy lube that was stuck in the barrel from live firing..., that same residual lube it was thought might trap moisture and help cause rust. Now it's pretty much known that hot water just causes "flash rust".
So water, and you can use soap if you want, followed by a clean rinse, and some damp patches to clean out the fouling, then patches to dry, and then lube up the bore with a rust preventative.
LD