I use ED's Red as my primary cleaning solvent. But for the hard/stubborn spots, I use Butches Bore shine solvent in a Glass Jar. This cleaner will remove all of the stubborn spots. I would also recommend using some kind of guide to keep the solvents from the trigger group. If you decided to clean from the muzzel ( not recommended) Make sure you use a crown protector. I use only Syn Oil's and grease as my lubricants. Protect better, last longer, have a much larger range of operating temperature.