.22 ammo has definitely become less of a fouling problem over the years.
When I first started shooting back in the early '50s, it was pretty mandatory to clean .22s after every session.
Now, I concentrate more on the actions, and usually run a Hoppe's swab through the barrel, followed by a dry one when the actions get scrubbed. That's about it for the barrel.
Center fire, I usually clean after each use, barrel and action. I use a lot of cast lead bullets, and its easier to keep them scrubbed out, than have to do a major de-lead operation. I use several different solvents, depending on what I need to concentrate on, - copper, lead, powder fouling, or all 3 sometimes.
