I use Nature's Specialties, but its expensive and hard to find. Only one store near me sells the brand. I used to work in the boarding kennel that the little store is hooked on to and people would always ask the groomers what they use because their dogs are so soft when they are done. http://www.naturesspecialtiesmfg.com/

Please note that an unusually soft coat and itchy sensitive skin can be an indication of a hormone problem or Cushing's disease or alopecia with any sort of cause. If the dog is overweight or drinks and urinates a lot it could be cause for concern.