Immediately remove the battery/power, then use a bunch of silica gel packs that have been dried out instead of rice (enclose them in a bag with the laptop): They're commonly available and won't get into things and cause problems down the road.
Alternately, just take it apart as much as you can and set it in front of a fan to dry out.
Keep in mind, it might be too late but it's worth a try.
If you really want to try and save it and are tech savvy, try tearing it down and giving it an isopropyl alcohol bath but if you aren't, it'll do more harm than good. Keep in mind ISO can damage some parts.