I clean my damascus guns the same as moden steel. Some of my guns have pitting in the damascus barrels. They are more difficult to keep clean and I believe it is more important that they stay clean in order to prevent further pitting.
I usually clean those guns with a spray like Remington gun cleaner and a bronze brush wrapped with 0000 steel wool chucked into an electric drill. After burnishing the bores with the drill, I swab RemOil in and push clean patches through until the bores shine.
I do have one W&C Scott hammergun that had 'sewer pipe' bores. I shipped it out to Steve Bertram for measurement and subsequent reaming and choke adjustment to clean them up. Normally though, I fall into the camp that holds that pitted barrels are not going to be made stronger by honing out metal...Geo
