So I couldn't resist using the Mr. Clean Magic Erasers I got the other day.
Even though my Macbook wasn't that dirty you can see the magical effects it had on the top case. Please take a look at the zoomed in part. Judging from the enormous cleaning abilities of these little bad boys I'd say it is enough if you use this sponge once every two months. Well, this was it for now...I will be writing a more detailed cleaning tutorial (describing my cleaning ritual) soon.
For anyone who is interested in how the Magic Erasers work check out these links: