Just like you exfoliate your skin, a good scalp scrub will remove dead skin cells/dandruff from the scalp surface. This step is crucial as it allows proper penetration of products used thereafter.
If you have thin hair or your hair isn't growing, then adding this step to your hair care routine will help renewal of skin cells which help hair to grow. Also, if you have greasy hair, this will soak up all the oil which regular shampoo can't do. Do it once a week for healthy hair.
Here is an easy home remedy you can make.
In a ¼ cup Himalayan pink salt or rock salt, add 1 tablespoon raw apple cider vinegar, 1 tablespoon coconut oil, melted 1 teaspoon Manuka honey and 15 drops essential oil of your choosing.
To use, wet your hair and gently scrub a tablespoon sized amount into your scalp using your fingertips. Let it sit for 5-10 minutes before rinsing with warm water.