You'll need to open the system up and inspect things. As your spoke about using Rice was this system wet at some point? If it was then you likely have liquid damage.
While Jessa talks about using Isopropyl alcohol to displace the water. I do things a bit differently as I often see the computer after it has dried out.
Again the issue is not the water (H2O), the problem it's whats dissolved within it! Minerals, Salts and other biological stuff. Pure water (Distilled Water) will allow you to wash away the junk. The idea here is to bathe the parts discreetly to rinse off the materials we don't want. You may need to use a soft brush to scrub the areas to get off any thing thats stuck down. Then we need to displace the water using Isopropyl alcohol.