If you want to see for yourself why you should run a wet patch down the barrel (breech end) before the first shot of the day, take at look at that very patch especially after the gun has sat for a few days. Copper, other metals, and solvent will have leeched out of the pores of the barrel. Your first patch will have a green tint and some black from unburnt powder and other residue.
My rule of thumb is, 1) one wet patch before I shoot that day.
2) If I'm shooting for an extended period that day, then a brush (dipped in solvent) followed by several wet patches until clean.
3) End of the day is a wet patch soaked in solvent to loosen the residue, followed by a brush dipped solvent to work the crud loose, then as many wet patches as it takes to remove all residue.
Finish with a patch that has a few drops of oil to leave a light film the entire length of the barrel.
Paul--