I would cut it off and use a rag with a slight amount of water and clean it upside down so gravity does not make the water go into the keys. I would dry it then spray it with a compressed air can. I don't know if this would work or not so use at your own discrestion. Just an idea.
Okay, so searching for "ways to clean your DS" seems to only pop up with ways to clean your screen, problem is my screen is fine
On the other hand, one day i decided to put chocolate and DS in the same pocket on fairly hot day. Suffice to say i'm still crying. =(
What is the best way to clean the DS R/L keys from chocolate?...

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