Rice doesn't do much, you need a proper desiccant. Take the computer as completely apart as you can, put the components in fine mesh bags, and bury the bags in silica desiccant gel. If you have silica crystal cat litter, this would work, though it's not as optimized for this sort of absorption as finer gel is. Leave it for a few days. This method isn't a guarantee, but I've used it to salvage machines, including a couple laptop computers that were soaked by a faulty fire sprinkler (those sprinklers are full of nasty water, so I cleaned everything with distilled water before drying). The one thing that is very difficult to take care of is water inside the screen, but some screens are sealed better than others.