For Lush, the key to great hair starts with a healthy scalp, and inventors at the brand have been developing products touted to will take consumers’ hair care routine to the next level.    From treatments to shampoos and styling products, efficacious ingredients include fruit juices, sea salt, honey and bananas to cleanse and leave hair shiny and soft, according to the company. New Hair Treatments  AHAA Fresh Scalp Treatment ($28)— Formulated for congested and oily scalp...