Another method is to use a hair dryer. Be careful not to overheat anything, but don't over-worry about that. Most of the components can withstand temps of up to 85 degrees. Use your common sense to judge how much heat you can apply.
Make sure you blow into every nook and cranny. Let it cool down again before you turn it on.
The silica gel is a good idea, but once moisture has lodged itself firmly enough to interfere with start-up, the silica gel alone may not be effective enough to get the computer working again, at least not for a long time.