Bad Corrosion: This method is last resort!
Go buy a brass .22 caliber gun barrel brush. You dont want to do this but once or twice in the lifetime of the bay, though. Chuck the brush in a cordless drill, lightly coat the inside of the port with good contact cleaner (use q-tip), and give each port a quick one second spin with the brush.
Obviously, make sure there is no signal running through the bay (power down the board) when you do this and use a swab to dry out any mess. Canned air will help to make sure no "hairs" of metal from the brush remain. Keep a close watch on the wear on the brush, as it wears out, hair will seperate. Swab each port clean and dry. Follow up with "regular maintenance" method.
Not So Bad Corrosion:
Same method but nylon .22 cal brush. Make sure no longer than one second spins! Plastic, friction, heat, your console's TT patchbay. Not a good mix, so keep it short! Swab each port clean and dry. Follow up with "regular maintenance" method.
Just Regular Maintenance:
Q-tip with contact cleaner. Another way is to use a TT connector with a little contact cleaner on it and run in and out of the port a few times (may have to sacrifice that connector though.
Any good electronic contact cleaner will work, but I use DeOxit.
Audio is fun, but no one said it was easy.
Doc