Regular use of the Rosemary Oil in getting rid of dandruff and also grows the hair stronger and longer. Rosemary oil is an amazing natural oil. Rosemary oil is one of the most popular oils for its wide array of benefits. It has become increasingly important and popular over the years. Rosemary essential oil is beneficial for dry and flaky scalps. Regular massaging of the scalp with rosemary oil nourishes the scalp and removes dandruff.