Remember, cleaning your gun is important, but "barrel break-in" is not: http://www.6mmbr.com/gailmcmbreakin.html

 Gale McMillan, of McMillan Stocks fame, was one of the finest barrel-makers and benchrest shooters of all time. Here he argues that elaborate barrel break-in procedures do more harm than good.

Comments collected from Gale's Gun Forum postings.
As a barrel maker I have looked in thousands of new and used barrels with a bore scope and I will tell you that if every one followed the prescribed [one shot, one clean] break-in method, a very large number would do more harm than good.