Ahhh Beer line cleaning....
This has been an obsession of mine recently, as I am having to troubleshoot off flavors in some draft accounts. My own keg lines I clean with a keg of PBW or Oxyclean, and rinse with water. This has been a general cleaning procedure that I do not as often as I should.
It's good that you have fixed your off flavor in you draft system, Bill. The best source that I have found for draft line cleaning comes from
Micromatic. That makes sense because these guys fucking know draft systems.
My suggestion for general line cleaning is to use Beer Line Cleaner at least every other week or when you tap a new keg. BLC is caustic and will remove any organic material from your lines.
Be sure to follow the instructions on the bottle! This should remove any bacteria or funk from your lines. Less often, but equally important, is to flush your lines with an acid. A long soak with an acid and a rinse with water can remove any minerals (beer stone) from your lines. I'm not sure how well star san or saniclean will work, but they should do a decent job with a long enough contact time.
Neither of these were specifically designed for this purpose, but I don't know of an acidic line cleaner available to homebrewers. Also, it's not a bad idea to replace your lines every year or so (and be sure to flush the fresh plasticy goodness out of them

)
Cheers!