What are some good methods of recovering key function after a spillage?
Apple are very likely to repair this under Applecare with no charge. I have had several defective keyboards and stuck keys in the past. In all cases, Apple replaced the keyboards for free under Applecare. 

Clearly your milage will vary, since if you have damaged the keyboard by misuse they are under no obligation to fix it, but in my experience, Genius bar engineers will always give you the benefit of the doubt.