I use a bag of cotton rags I get from the auto store. I cut out little squares with a scissors. I would say I rarely use patches except as a way to apply oil.
Just note that if you're passing CLP through the barrel, I think you may find it surprising that you're doing a heck of a lot more than other people. It's sort of like car wax. If you went outside and waxed your car just twice a year, you're doing more for your car than someone does in its entire life time. Yet oddly enough car cleaning products are always in business.
As far as how many patches it takes, that entirely depends. Sometimes you may get a false reading if you use a brass brush in between cleaning. Also, sometimes if your chamber locking lugs are really dirty, sometimes the patches may pass that area and pick up some debris and you'll find yourself in a endless loop where the bore is clean but you're still getting black patches.
With that said, I like to clean the locking lugs area first and the muzzle/flash hider area first. I don't know how many patches but usually pretty easy. The hard part for me is the bolt carrier internals. I'd say 20 patches sound about normal to me.
Some tips, I found helpful:
- Soaking and heat are the best way to clean. If you can run a bore snake through your rifle immediately at the range before packing and while the barrel is hot, you'll find it a lot easier to clean when you get back at home. Also, if you allow CLP, solvent, or anything to "soak" for a while, that will help also.
- Get some nylon brushes along with brass brushes. Nylon brushes really help with cleaning once you pass the initial brass brush.
- Try to get it as clean as possible by soaking a patch until it comes out slightly grey in color. Once a soaked patch comes out slightly grey in color, you're good to go to pass a patch until it comes out clean. Think of this. If you're washing dishes, what is the best way to clean? Covering a dish with soap, then scrubbing it? Or is it better to use a soaked pad and scrub until clean, then wash it off with water, and then finally a towel?
- Get a dedicated solvent/cleaner instead of using CLP. Something like Hoppe's No 9 or MPro7 Cleaner are going to get you off a lot easier.