I have always likes Hoppes. Here is a simple cleaning procedure:
I use a one piece cleaning rod, Hoppes gun vise, and use a jag set (including 12 guage).
http://www.hoppes.com/GuidetoGunCare.pdf
Be sure the gun is unloaded and all ammunition has been
removed from the cleaning area
1. Attach the bore brush to the cleaning rod and
moisten with Hoppe’s No. 9. Starting from the breech
end of the barrel, when possible, work the brush
back and forth to loosen residue and fouling. Ensure
the brush passes completely through the barrel
before drawing the brush back through the barrel.
Starting from the breech end guards against any
accidental contact between the metal rod and the
finely-machined rifling at the muzzle tip and reduces
the amount of fouling, deposits or metal fragments
that may fall into the action.
2. Remove the bore brush and attach a slotted end to the cleaning rod. Insert a cloth into the slotted end and, starting from the breech end of the barrel, push the cloth through the
barrel. Remove the cloth and repeat process until the final
cloth comes out clean. This will remove any lead and
powder deposits. If you’ve been shooting with copperjacketed
bullets, you’ll need to use Hoppe’s Bench Rest 9®. Bench Rest 9 has been specially formulated to cut copper, as well as lead and any other build-up in the barrel.
3. Now that you have finished cleaning the bore, attach a clean patch to the slotted end and moisten it with Hoppe’s Lubricating Oil and run it through the barrel once. This will put a fine coat of oil inside your barrel to prevent rusting.
4. Using your utility brush, clean dirt and materials from the gun’s action. Moving parts such as the action and trigger mechanism can be wetted with solvent, then scrubbed with the brush. Any type of Hoppe’s solvent can be used. The larger bristles on the utility brush can be used to clean any broad surfaces, while the smaller bristles can be used to get into hard-to-reach areas.
5. After you’ve scrubbed with the brush, wipe the area clean
and apply a light coating of oil. Wipe all metal surfaces clean and lightly oil.
6. Finally, wipe all exposed metal surfaces with a light coat
of oil.