Sesame oil is something we use in most of our spicy dishes like vatha kozhambu, for seasoning dosa, idly. This oil is also known as Gingelly oil or queen of OIls. We use this oil to lubricate our skin before taking bath. We use it everyday before bathing. It plays a vital role in Indian cooking. In Tamilnadu, this oil is been used to give first bath to young infants. Grand mothers usually warm this oil with a pinch of Omam (kalonji), rice and black pepper and drain those ingredients from oil and use the oil for giving bath to young kids.
Source:- www.wikipedia.org

Sesame oil is also used by adults to take oil hair bath because it is a belief in India that sesame oil reduces heat in our body which in turn reduces hair loss. It is used as a preservative for making pickles. It is also considered as a divine oil which is used in Pujas or lighting silver and brass lamps.