How to clean clear cables on these machines?

[eraser]

Since Apple used clear USB & power cables on all of the iMac/PowerMac "colored" machines I am sure you have all run into cables where the plastic/rubber turned dark from something in its prior home.

How can these cables be cleaned? Or if they turn brown from something in the environment is that permanent? What (if anything) has worked for you?

Thanks

 

[Byrd]

A "magic eraser" works a treat on cables, with a little soapy water - they come up like new.