Well Baer, It's probably not time for such unusual and heavy artillery right yet.
Lorenzo, Baer is right about the humidity. Mold will only grow if conditions are too damp - generally 65% RH or higher. So the first question to ask is, where was the pipe displayed? The display area (or basement storage?) needs to be changed.
To clean it, let it dry right out and then wipe with a clean cloth. I like cotton flanellette. You can also try some soft swabs for the inside.
Solvents / Listerine (!!!) can affect the finish/sheen in a negative way. Unless you are sure what you're doing, I'd steer clear of that, and even if you are sure what you are doing I can't recommend Listerine!
If the display area can't be changed (best possible option), you'll need to get some conditioned silica gel (40 - 5-% RH) into the frame, and then seal the frame using a moisture barrier like Marvelseal.
Sealed framing systems have been discussed here so try the archives. If that doesn't work, someone can direct you to one of Hugh Phibb's very good articles on the subject.
Good Luck.
Rebecca