I once managed to spill a bowl of rice crispies and milk over a desktop A1200! The bowl landed upside down on the case, right over the cooling slots :-o
Luckily the power was off at the time. I had to completely strip it down and painstakingly clean up the sugary milk residues that had found their way round every component on the motherboard! I had to wash the case itself!
I then let the thing dry out for 2 days.
Amazingly, it all worked afterward :-D