I've dismantled a couple of keyboards after spills. These were pre usb types so they may have changed since. However, if I recall correctly, they had three plastic layers under the keys. Between these three layers liquid could get trapped and I'm not sure that hot air would have dried them out. I separated the layers and dried them out with paper towels. Mostly they worked again but the wires could get damaged where they entered the keyboard casing. If that happened they were dead.