MEN: Removing Hair Product Buildup

First, when in the shower before wetting your hair, add shampoo to the hands and emulsify into the dry hair until you achieve a light lather. This will loosen the waxy buildup and make it easier to remove. Proceed then to rinse and repeat on wet hair. You can do this for a few continuous days for better results.
A helpful trick when applying the product on clean hair is to lightly spray your hair with hairspray then apply the product, making the waxy product stick to the spray and less on your hair.