Clean banana plugs?

I know that these tend to get a little dingy over time. Is there a particular method for cleaing them or restoring them to their original luster? I have a set that is looking a little dull.

http://shopping.netledger.com/s.nl/c.ACCT113328/category.82/it.A/id.2002/.f

I got some of that cleaner from Radio Shack and it cleaned 'em right up. Thanks