Dave, That is pretty much the idea I had gotten with the liquid Lava soap - remember? I had the same problem with a .45 Hawken. But that Lava cleaned it up nicely.
When you think about it, its pretty funny what we run down our ML barrels to clean them. But we would think twice before using the same stuff on out centerfires! Yet most of our MLs will outshoot the majority of the CFs. Maybe we ought to rethink the cleaning methods for the CFs?