The Essations Tea Tree Solutions Dry and Itchy Scalp Shampoo is so wet that you can easily apply it to the scalp as a preshampoo. It has camphor and menthol in it. I sometimes use it to "self-cleanse" the scalp for those with braided sew-ins in order to eliminate loosening up the braids.
This shampoo is also moisturizing. After rinsing it out of the hair, your scalp feels much cleaner without stripping too much life from the actual hair.
When using as a pre-shampoo, apply and massage into scalp and let it sit for about 30 minutes before rinsing out. No heat necessary.