It is said that Navaratan oil is used in summer season only. But my experience says that it is very useful in all seasons, not because it feels cool but because it smothens the hair and gliters them . It cools our eyes and, in result , our mind. One feels different using the oil.
Moreover it is not costly and finds anywhere, in Kirana Stores , Departmental Stores and also in any Medical Shops as it is used as a medical prescription after exercises. Ayurveda also mentioned its use. It needs to have only some drops to use daily and thus saves the expendicture.
It is also used for the top of the head before sleeping which brings calmness in the morning. Because of its fragrance, no need to purchase any another oil for the fesivals like Diwali in India and thus saves the expendictureand thus saves the expendicture.
The people around the user of this oil are always praise the user and come nearer to him and thus it is socially useful to the user.
No harm to use this oil to any part of the body.