Should I be worried after this?

Question

Five days ago I made the mistake of eating cereal near my MacBook.  The bowl flipped and milk spilt all over the trackpad and keyboard.  If I had to estimate, probably a half of a cup of milk went on the trackpad and keyboard.  A lot of milk nonetheless.  After rapidly cleaning the milk off of the MacBook, I immediately powered it down and kept it off for three days.  On the third day I attempted to power it back on... and it worked!
It's working fine now.  At first a couple of keys were sticky but after pressing them a couple of times they were back to normal.  The backlit keyboard still works fine.  The trackpad, at first, was making a weird sound every time I tapped (not clicked) it but that has recently subsided.
I know this voids my AppleCare warranty.  I called Apple and asked if I could bring it in just for them to clean any milk residue left over on the insides.  They said they would not do this and referred me to a third party Mac repair center, compumac.
I think it's best I go there (when I'm on spring break, I'm away at school currently) and ask them to open it up and clean any milk residue left over.
So, my question is, should I be worried?  I'm backing up all of my schoolwork on a flash drive just in case.  I feel like my MacBook could die at any time.  I won't know for sure until I bring it to compumac.  I'm just shocked that it is working flawlessly after I spilt milk on it.  What do you guys think is the best route of action to take given my circumstances?

Answer 1

Cross your fingers and hope for the best until you can take it to the service provider. There will be limits to how effectively they can clean some of the parts, particularly the trackpad's innards. The labor-intensive nature of cleaning and the impossibility of being certain everything is really clean are the reasons why Apple doesn't even attempt cleaning — they simply replace all the parts that have gotten anything on them. Compumac may tell you they'll do the same thing. Even if they clean parts instead of replacing them, it will be expensive, and you (and they) won't be 100% sure they've gotten everything. Milk residue anywhere inside will draw moisture out of the air in humid environments and lead to corrosion, and half a cup of milk is enough to leave a lot of residue inside. Some of that is likely to remain even after the most thorough cleaning that can practically be done. So chances are that even if you have Compumac do their best, you've shortened the useful lifespan of your computer by some unpredictable amount.