Is it really that easy for someone to clean their .22 wrong and damage the barrel? Wouldn't a guy have to really be ramming something wrong sized?
It is very easy for someone to damage the muzzle of a firearm. A bore guide is mentioned but most of the people who are "cleaning" the rifle do not use one. Cleaning a rifle from the BREECH end is much better than cleaning the bore from the MUZZLE end. It is very difficult for someone to ram a cleaning rod straight down the muzzle without touching the sides of the bore. This creates an abrasion at the muzzle and damages the crown of the rifling.
The British Military recognized this wear on the rifling, although they still kept issuing a cord for cleaning the bore for the various .303 rifles. Many soldiers held the rifle by the muzzle end, and pulled the cord with the patch through from the breech. The only problem was that the rifle could not be kept perfectly steady so that a straight pull tended up to be a sidewards pull, and the cord wore on the muzzle. This was especially worse if there was a bit of dirt or grit on the cord when it was used.
In a lot of rifles, especially military ones fired with steel jacketed bullets and corrosive powders or primers, cleaning was necessary to prevent rust in the bore. Standard was two quarts of hot water down the bore, followed by patches in the case of the .303.
In the cases of older 22 rifles, there is always the possibility of finding bad bores. Corrosive ammunition was used in a lot of them and it was still available before WWII. However, with modern non-corrosive .22 ammunition and lead bullets, a .22 rifle in most cases will outlive it's original owner and still give acceptable accuracy. This does not suggest that you can store it in a damp or salt water place and expect it to stay pristine, but using a bit of common sense will prevent that.
I have contributed many pounds of lead to the prairie provinces while pursuing Gophers, and did not clean the bore of my .22 rifles. The accuracy did not seem to be affected, much to the dismay of a lot of unlucky Gophers who happened to be at the same place as a fired .22 rimfire bullet when it arrived.
So, if you MUST clean your .22 rimfire bore, then use a bore guide, and if you do not have one, clean from the breech end, NOT the muzzle end.