You use vinegar (an acid) on Alkaline batteries (a base). The reaction between the two polarities causes the cleaning action. This works perfect for situations such as the Wii remote mentioned. I recently fixed a clock & my Wii Fit with this method as well (AA Alkaline Batts ate them up).
Using those basic chemistry principles, you need to use a basic solution (such as baking soda) on caps to really clean up as they're usually sulfuric acid inside, correct? Unless I'm missing something about the composition of caps.
Also, nightrnr is correct in a previous post, do not remove if your console is a 1.6.
After removing this cap, I have this thread detailing how to connect to a time sever so your console will display the correct date & time

. Link:
viewtopic.php?f=52&t=50931