With any engine/ignition wetness issues the quickest and easiest way to eliminate the H2O condition is with WD40. Water displacement formula 40 will do just that displace the water that has infiltrate connections and other openings in wiring and componentry. On boats we never are out of WD40!
You can liberally spray the various components while trying to start the car in steps or you can just spray everything and just try to get things running and warm to dry things out. The piece by piece method could help diagnose the actual cause more specifically and is possibly worth the effort in the long run. or you could get it running and then wash the engine again to recreate the fault condition to diagnose at a later more convenient time, or wait until the monsoons season when if there is a possibility the similar wet engine condition will occur. Good luck!