I've posted before that Dog Training Ireland now has Little Beau's Salon onsite in Blanchardstown for grooming (and they will NOT trim a cavalier without an owner demanding that hair actually be cut off!!
Another cavalier friendly salon is Wizard of Paws, also in Blanchardstown. Be sure to explain exactly what you want done to Nathalie -- whether you want a trim or not. She also does washes and dries alone for just €10 -- given the state of my back, well worth it!! 20% off a full groom for anyone who has a foster needing a groom, or who owns a rescue dog from me. Nathalie: 086 215-3043