Getting him "groomed" twice a year usually means taking your dog to a professional "groomer" for a bath, perhaps blow-dry and special brushing, even a haircut for some dogs, depending on their breed/need. This is different than just brushing him at home, which is free! What would you call that in the UK?

On a silly grooming note, a groomer opened up shop not far from my parents house, and put a big sign out advertising a "wash and fluff-dry" and we always wanted to take our Great Dane-Lab mix, and ask them to "fluff-dry" her!