I use Sweets 7.62 as well. I've never tried CR-10, but Sweets gets crap out of the barrel that I haven't been able to remove with other solvents. The only thing I don't like about it is that it stinks to high heaven.

The electrical system is called Foul-Out. There are several versions made by Outers. Their cheapest one is about $90. It's not practical to use for regular cleaning, but I hear it does a good job on barrels with a lot of fouling. I have never used one.

I agree with many of the others about copper fouling. A little probably doesn't affect much, but a lot can cause problems. I try to get most of it out, but I don't get too worked up if I can't get it all.