Iv San Bernard teaches to leave shampoo and conditioner on for 5 minutes to get the most efficiency from the product, however the sequence of application is also important.
Our body, as well as our pet’s body, has different areas which are more sebaceous (secretory) than others. In humans, the most sebaceous areas are head, face, pits and privates. Those are the areas that secrete the most oils or fluids and are also the smelliest areas. In dogs, it is the face, chin, neck, under belly, pits, groin, anal region, and paws. Therefore, these are the areas to apply shampoo first, so it has the most time to work.
If you are doing therapies, always start on the most affected area. Many have been taught to start on the back (which is one of the cleanest areas of the body) out of convenience, not science. Sounds simple, but makes a big difference in our results.