Eucalyptus trees it is commonly referred to as Niligiri oil. This is one of the go-to essential oils if you are having cold and congestion. Add a few drops of this oil to boiling water and inhale the vapors. The anti-viral healing property of this oil is known to help decongest and loosen phlegm. The anti-inflammatory properties will help bring down cough. Eucalyptus essential oil is known to stimulate hair growth. Massage your hair with diluted eucalyptus oil to increase the blood flow to the follicles resulting in a healthy crown. Add a few drops of eucalyptus oil to your regular shampoo and massage your scalp well before washing it off. This might reduce the itchiness caused due to dry scalp. Eucalyptus oil is an oil that must be there in every home as it can be used as a insect repellant, use it to reduce body pain, cough and cold and also can be used to make a mouth freshener.rosemary oil is the essential oil that is extracted from the leaves, flowers of rosemary herbs. Rosemary oil can be used for &variety of purposes. It is valued because of its ability to strengthen the entire body. Rosemary has been used by the ancient romans, Greeks and Egyptians. It was considered as a sacred plant by the ancient civilizations as it was believed to cleanse the air and thereby prevents cold and cough.