Seriously Paul,
If you think that manual "scratching" may wear a hole in the horn, be vary careful about adding power tools to the equation - esp. a dremel that burrs at 20,000-30,000 RPM. 3M makes some 1", 2", and 6" cutting & polishing whhels of Scotch-Brite designed for removing burrs & polishing aluminum in homebuilt aircraft construction.
Cleaveland Aircraft Tool
www.cleavelandtool.com and Aircraft Spruce (800-824-1930) carry these.
Leigh may be kind enough to tell you his trade secret of how he accomplishes his magic.
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