I don't have a Furfrou myself but I have run into the salon that you go to to groom it. The location of this "salon" is on Vernal Avenue in Lumiose City. There are going to be two preschoolers in-front of the salon singing a "Snippity song". Also if your having finding Vernal Avenue, its right across from the Professors Lab.
Hopefully this helps!
~ Redwood63