I do deep cleaning about every 3 months for the pipes that are in my active smoking rotation (usually 10-12 pipes). To me, deep cleaning is to use some sort of alcoholic solution (everclear, vodka, rum, etc.) along with bristle pipe cleaners to clean out sludge deposits in the shank and sweeten things up a bit. Then I run regular pipe cleaners through until they come out clean. Reaming is something that I only do when it is needed, as is the case with the salt/alcohol treatment. Most of my pipes will never need the salt/alcohol treatment, which I only use for when I get estate pipes that are badly ghosted or generally nasty.