Oil-pulling is an ancient Ayurvedic therapy which involves holding vegetable oil in the mouth for ten-fifteen minutes and then spitting out the oil. In Ayurveda, oil-pulling has been used to strengthen the teeth, gums and jaws and also to prevent tooth decay, gum disease and bad breath. There is also a traditional belief that oil-pulling helps remove toxins from the body.
On the Internet there are many websites that claim oil-pulling can be used to treat and prevent a variety of diseases including liver and lung disorders, reproductive conditions, heart disease and even cancer. While I don't believe that oil-pulling is a panacea or can help cure every single disease that exists, I do believe that it has a place in daily lifestyle practice based on Ayurveda. It promotes dental hygiene and may help with detoxification and stimulation of digestive fire or Agni.
The practice is usually done with either sunflower, sesame or coconut oil. Basically one takes about a teaspoon of oil into the mouth and swishes and "pulls" the oil around through one's teeth. After about fifteen minutes the oil is believed to have drawn up toxins and waste metabolites from the body and should be discarded. It's better not to swallow the oil. After spitting, rinse the mouth well with water. The practice should be done on an empty stomach, preferably once daily in the morning.
If you are interested in trying oil-pulling I recommend practicing daily for at least 2 weeks to evaluate whether it has any effect for you. Unfortunately there is no scientific research on its efficacy at this time, but research would be important and helpful to elucidate this ancient Ayurvedic therapy.