Body scrubs remove dead skin cells, and so provide several benefits: They allow your skin to absorb moisturizer better. By doing dead skin cell buildup, any moisturizer applied afterward will soak into the skin more thoroughly. They unclog pores and prevent ingrown hairs.
But Magically speaking, I like to use this one to cleanse myself energetically. Scrub your body before taking a bath, while your skin is wet. Then bathe as usual.