Eucalyptus (Eucalyptus globulus) essential oil is one of the most popular essential oils as it's easy-to-use and very effective. So, what is eucalyptus oil good for? Eucalyptus leaves have a naturally sweet aroma but through proper distillation, the essential oil becomes brisk and camphoraceous, so using a diffuser provides multiple benefits. This essential oil is especially good in salves, muscle rubs and clarifying diffusions.