I always tell my groomer to use Coal Tar shampoo in summer, it relieves the itch from bug bites and I like the smell also. Or the Oatmeal and Baking Soda if he is out of Coal Tar. Miracle Coat shampoo and conditioner is also great for my dogs.
My vet and the breeder warned me about bathing too often though, it dries their coat and could lead to skin problems. They recommend 3-4 baths /yr.