Carbonated beverages are among the worst (plain water is bad enough)
on electronics, since some of the brands have phosphoric acid or other
ingredients that can speed up the corrosion process. Along with sugars
or corn sweeteners, the ingredients are among the reasons why a DIY
cleanup of spills cannot be performed at home by a casual user. - Even
diet soda has difficult to remove chemicals that can corrode electronics.
• Cleaning your Apple products - Apple Support
If liquid does make its way inside your Apple product, get help from an Apple Authorized Service Provider
or Apple Retail Store as soon as possible. Liquid damage isn't covered under the Apple product warranty or
AppleCare Protection Plans. If you plan to visit an Apple Retail store, make a reservation at the Genius Bar
(available only in some countries).
The unit likely will require major take-apart, if it can be cleaned; that's where
the logic board & internal parts get professional treatment. Not all shops can
or will be able to do this. Your Apple professionals can discuss your options.
Good luck! 🙂