Cleaning MacBook Pro Keyboard

Recently I had a spill of mountain dew onto my MacBook Pro keyboard. Everything is working fine except the arrow keys, shift key, and return key are sticking. They don't stick for very long, just kind of hard to press and it takes a second before they pop back up. I've taken my computer to an Apple store and they told me there was no way of getting the metal piece off to get to the back of keyboard and I'd have to order another one which costs $334. So I was wondering before I go that far if there was any chemical I could spray into the keys that would clean the mountain dew and evaporate, or if there's some way of popping the keys off to clean under them.