something ive found helpful for excessive barrel fouling is use a bore brush a size bigger, for example your gun is 22 cal use a 25 cal brush just make full strokes dont change directions in the middle of the barrel that could cause you to scratch the bore. My 45's get a lot of lead fouling since i shoot mostly lead cast reloads my 45 bore brush is a bit on the small side since its cut to be used in a 40 cal aswell I found a 50 cal bore brush to work great. asfar as solvents go I found the a 50/50 mix of kroil and hoppes #9 to really get the lead loose, but if its a fairly new gun theres a good chance of having rough spots in the bore that just grab lead like no tomorrow and the lead basically solders itself to the rough spots, in this case you will want to use JB bore paste and clean the bore after every 50 shots with the bore paste for the first 500 rounds this will ensure a good smooth, rough spot free bore. good luck