Thought I'd share a recipe I found in a VERY old hunting book. One part whale oil ( I know, it's impossible to find nowadays, but read on, I'll get to that!), one part turpentine, and one part acetone. Whale oil was used as the first hydraulic fluid in automatic transmissions, and later replaced with the red stuff we are familiar with today, so good old (new?)ATF is a reasonable substitute for whale oil. I store this magical elixer in an old Hoppes bottle. Just make sure it is tightly capped when not in use as the acetone evapourates quickly. Does an excellent job of cleaning the bore, and any other part for that matter on a .22, but won't touch copper fouling one bit. Doesn't really matter, as .22 pistol/rifle fouling is almost all bullet lube and powder residue anyway. Econmical too, as a 3 ounce bottle costs about a quarter. I've been using this stuff for years on my .22s and shotguns, works great. As a side note, my wife finds the "aroma" of Hoppes #9 nauseating ( I LOVE it!!) but this homemade stuff doesn't bother her.
steve