You can't really over clean one, but you can over oil them. They really don't need much oil at all.

Some rifles shoot better with a "fouled" barrel if you are looking for the utmost accuracy, so some rifle shooters will not clean a barrel until it needs it.

With a smooth bore shotgun though I would say run a patch down it and wipe off the metal surfaces after every shooting session. Won't hurt anything and it will get you familiar with your gun.

You really don't need to strip the whole gun down every time you shoot it though unless you got it really dirty or wet. Again doesn't hurt anything either as long as you don't mess it up putting it back together.

Paul