ShopTalk: Reducing glare on a shiny putter head

[Don M]

I have to cut the glare on an aluminum mallet putter.   I have always heard 
gun blue is the thing to use, so I went to Wal-Mart to get some.  Their 
package of Birchwood-Casey PermaBlue says it will not work on stainless 
steel, aluminum, or other non-ferrous metals.

Seems like paint will have a chipping problem.
What would be good for this?
-Don M