I got a very rudimentary system for cleaning my disks--and it has worked for the past 6 years on any system.
Get five or six Q-Tips, two soft tissues (or toilet paper if it' softe nough) and a sink. Gently wet one side of each Q-tip and run it over the dirty, rimy, etc. parts of the disk. -NOTE DO NOT GO OVER THE LITTLE RING IN THE MIDDLE. IT'S SHINY. DO NOT TOUCH. KAY- and just get the entire thing moist. Use the dry end of each Q-tip to thin it out over the disk in all sides. ONLY RUN IT OVER THE CENTER RING UNLESS YOU ABSOLUTELY HAVE TO.
Once the water is all thinned out, make sure to apply some pressure when applying water--and thinning it out--get the tissue and/or toilet paper and gently run it over the disk like you're cleaning eye-glasses. Go in soft circles, pushing the water, per se, to the edges of the disk until it's completely dry.
EDIT: But be smart and DL the game to your harddrive so it doesnt rely on your darn disk.
Aloysius:
-Less than half a of percent of players have the General rank on Xbox Live.
How is the General rank fair again?
Halo Fanboys. The next most annoying thing next to Jonas Brothers fanboys.