Matt,
The duo is a pain to work on so I don't like it, but what I do is
take the whole thing apart, remove the belts, wash all the plastic
pieces and the drives with a very mild soap in very hot water (being
careful not to get any water in the motors or bearings). You really
need a small hose you can spray with to do this accurately.
Then I shake dry, pad dry any water drops or steel parts with a
cotton cloth, and let dry at least 24 hours.
At that point, I'll clean the head with a cotton swab and
headcleaner or alchohol. If I use alcohol, I'll go back over the head
with a DRY swab to help dry the water out faster.. you don't want to
leave water sitting on the heads.
While you're in there, check the felt pressure pad above the head.
It should still be fairly cylindrical and not too dirty brown or too
squashed. I think the life of these drives will be more measured in
felt pad life than any single other part.
I agree with the other fellow -- a cleaning disk -- especially a
dry one -- is the worst thing you can use on a very dirty drive.
They're fine if used miniminally for maintaining a drive that was
thoroughly cleaned before, and you're just removing disc debris (not
aerial dirt / dust).