The cider vinegar treatment works best when applied to a wet coat, not directly to dry skin.
Every dog bath at our place, except for the very rare appearance in a conformation dog show, ends with a special rinse. 1 part apple cider vinegar, 1 part brewed green tea (cooled), to 4 parts distilled water. It's the final rinse after the shampoo is out but coat and skin are still fully wet. Immediately towel and then blow dry. I've had dogs with sensitive skin before, had lots of allergy sufferers, but never had a problem. It does help with the itchies. So long as you get the dog thoroughly dry, no sweet pickle smell!
