Is there a product or process which helps in cleaning the face of the cylinder on a revolver? And what about that line on the frame above the cylinder/barrel gap?

I found that one of the soft lead removal cloths will clean the face of the cylinder of my stainless S&W easily. Just a few seconds of polishing and it's clean as a whistle.

I have not tried it on a blued pistol. I would use caution there as it may remove the bluing.

Scotch Bright & #9