|Both types can be cleaned. Not an easy task. |
Do NOT attempt to turn a laptop on without cleaning the KB. If this is a laptop you should remove the keyboard for cleaning. Some additional disassembly may be required. Plain warm water will due. Rinse with distilled water and leave it set until thoroughly dry.
As HopperRox stated, it may be easier to buy new.
Google for how to cleanup a spill on a keyboard. You will see lots of hits.