Would there be a solid residue left behind from a reaction between NaK and H2O?
According to this site:-


  NaK reacts explosively with water to form hydrogen, potassium hydroxide
  and sodium hydroxide.


This site says:-


  NaK is a strong reducing agent. It is corrosive and will react violently with water. The reaction with water will liberate extremely flammable gases potentially causing a fire or explosion. 


This youtube video confirms the above fact.