Rosemary promotes hair growth and peppermint offers cool relief. Rosemary and mint work together to stimulate the scalp while being gentle anti-bacterial agents. To use simply wet your head, rub the soap on your scalp a bit, and then lather up and massage/wash as per usual. Rinse well, and (optionally but recommended) follow with a vinegar rinse to keep your scalp's pH in balance or the conditioning bar for a soft finish that super hydrates your hair.
An added benefit: shampoo bars eliminate packaging--particularly plastic bottles, so you are being both kind to your head and kind to our planet.