I have used JB's on a couple of old rifles that were not cleaned properly through the years as well as a couple of .22's that just had tons of rounds through them. I would not rcommend it though for general cleaning.
I read the pages (links below)from the 6mmBR site amd picked out what I thought were the top components for me. I liked the idea of the spray on carbon remover but in past experience, it always seemed I ran out of something in a can long before I did a liquid in a bottle. I chose to go with the TM Solution for the carbon and the Butches Bore Shine for the copper. I also keep a bottle of Sweets on hand for the heavy duty cleaning. A small bottle of Kroil is also helpful for an after cleaning oil of the barrel. The stuff will get into places standard oil will never see.
Here are the links :
Bore Brushing--How Much is Too Much?
Bore Cleaning Methods & Products
Another thing I switched to and it has helped, with what your referring to in reguards to false reading on the patches, is a Tipton Ultra Cleaning Jag - Nickel Plated Brass. I have found that this will definately cut down the false reading almost completely. I use 1 3/4" patches, which cover the entire length of the jag so as not to allow contact with the bore. You might have to try different patches with them as they run just a tad bigger in doameter than regular jags. I found that using Pro Shot patches with the nickle plated jags and Tipton patches with the standard brass works just fine. The Tiptons run just a tad thicker, and you can still use them with the nickle plated jag if you just drop down a caliber size. I only use these for .257, .277, and .284 since these are the main calibers I shoot. They are also the highest velocity and seem to foul just a tad quicker.
hope this helps,