I have several Nylon 66's. When purchased a few had so much gunk in them, it required a "putty" knife to clean. And yes I can take them apart. They worked dirty, So? The rifling in a 22 magically does not get fouled??
Yes, you can shoot thousands of rounds through them as you can any gun. The infamous Glock, XD, Berreta tests. Doesn't mean that accuracy does not suffer. I only used 223 as it is a 22 bullet.
So apples or oranges it still is no "proof" that a 22 is any different than any other caliber. Find a statistically valid test that proves a 22 need not be cleaned??
It's a firearm like any other tool, it needs to be cleaned.
This article is about Marlins but the gist is the same. It's even written in Western Wisdom
Western Wisdom: Cleaning a Marlin .22 Rimfire Rifle
No.
Unless you are using a propellant that creates hard crud in the bore (blackpowder) or shooting undersized cast bullets that are plugging up the rifling, you don't need to be cleaning the bore.
My Marlin Guide Gun is an example: Perfectly clean bore equals wide groups. After about 5-6 shots the groups have tightened up. My theory is that my Marlin's barrel, which has various restrictions from stamped nomenclature and broach-cut dovetails, gets filled in and smoothed out from the "fouling shots". This is true with jacketed and cast (more pronounced with cast).
Maybe if I owned something with an after market, high-quality barrel I would have different experience.
Regarding 22lr, I was simply passing on what the expert shooters do.