Folks think that using hot water helps to get moisture out, but in fact, it merely causes flash rust to form more quickly. Tests done years ago with the NMLRA showed that the barrels were no cleaner with cold, soapy water.
Soap and water will help to get out any residual grease compounds from bullet lube. The leftover ash in the barrel combines with moisture in the air to form acidic compounds, and the soap as it's a "base" also counteracts this.
Scrub with a muzzleloader bore brush, as a regular, copper, bore brush may jamb in the barrel while a muzzleloader brush is designed for the back and forth movement in cleaning a muzzleloader barrel.
Rinse with clean water, and then dry with cloth patches. Some folks swab with rubbing alcohol first, as this helps absorb the water. Some folks use a patch with a good amount of WD-40 applied. Many folks follow this with Birchwood Casey "Barricade".
Some folks like to also use a pipe cleaner on the flash channel from the nipple area into the breech. Apply rust preventative to the threads of the nipple and reinstall.
Rub the outside of the barrel with rust preventative and reinstall on the rifle. Store muzzle Down, for the next day or two, to keep any of your rust preventative from rolling down into the flash channel.
Check the next day with a clean patch for any rust, and you might reswab the barrel with Barricade.
LD