By dry brushing one can promote better body detoxification by improving lymphatic circulation. 

The lymph system absorbs, transports, and recycles products from the interstitial space (tissue space). The products in the lymph system include proteins, water, cells, fats, cell debris, white blood cells, cancer cells, bacteria, viruses, and many others only the lymph can handle.

Lymph vessels are mainly located at the skin and subcutaneous layer and can be found throughout the entire body. 

Below is a video that will help you understand how to effectively dry brush.