Sandalwood has been popularly used in many different acne treatments and skin treatments in general.  This essential oil has been known for its ability to work as an astringent, a cooling agent, and a moisturizer as well as an antipyretic, antibacterial, carminative, and sedative to the muscles.  They claim it also works as a nervine, expectorant, and diuretic while helping to regenerate the human skin cells.  This being said, it has been traditionally used by Ayurvedic practitioners in traditional medicine for the treatment of multiple conditions in general.  It has been able to address most skin problems, especially those that happen to be related to bacterial sources, and it has been used in various cosmetic products.  Its use in acne of course in part comes from its properties as an antibacterial and antiseptic, and for many, it has been quite soothing to the skin, of course not actually causing irritation or otherwise.  Sandalwood has quickly become popular in part because quite frankly speaking, it also has an earthy and pleasant aroma.  It has therefore also been used in aromatherapy.  However, its main benefit as for the moment seems to be for the treatment of skin problems such as acne as well as just soothing and taking care of the skin in general.