Are graphite intercalation compounds stable in water?
According to "Graphite sulphate – a precursor to graphene", Siegfried Eigler, Chem. Commun., 2015,51, 3162-3165:  


  Graphite sulphate is used as a precursor to graphene for the first
  time. The positively charged graphene layers react with water to yield
  a processable graphene derivative.


This would seem to imply that it would indeed de-intercalate in a beaker of distilled water.