I remember the first firearm I ever cleaned was a Marlin bolt action 22LR rifle.  To clean the gun, all you had to do was pull the bolt out the back by depressing a button and pulling it back.   You could look down the chamber and see all of the fouling and know how dirty it was.   Using Hoppes cleaning solvent on a wet patch would produce a dark black gun patch on the other end when pushed through with a cleaning rod.   After you did that a few times, I’d run a cleaning brush a few times and then run a dry patch until it ran clean.

Revolvers and some semi-auto guns like the M1 Garand or the M14 and Mini 14 can be tricky and need to be cleaned from the muzzle if you are using a cleaning rod, well a few decades ago a new innovative way of cleaning these firearms was invented.   The Hoppes boresnakes are the simplist way to speed up the process and to put dangerous wear on your barrel by using a cleaning rod.   The Hoppes Boresnake is caliber specific so you may want to pick up a few for various calibers.  There are also rifle and pistol versions.