I've done oil pulling in the past using coconut oil, but never did it long term to study any overall positive effects. Some immediate results besides the feeling of clean teeth, was expelling some mucus that was in the throat area, that was almost immediate. Here's an article worth a read...
The Science of Oil Pulling
One of the reasons oil pulling may be starting to gain mainstream media attention is because there have been some studies conducted recently that have at least validated some of the dental health claims.
A study published last year in the Society for General Microbiology, titled “Coconut oil could combat tooth decay,” reported that “digested coconut oil is able to attack the bacteria that cause tooth decay.”
The study used enzymes to simulate a “digestive” state of coconut oil, but swishing the coconut oil around in your mouth with the natural enzymes in your saliva could easily provide the same benefit.
In a study published in 2011 in the Journal of the Indian Society of Pedodontics & Preventive Dentistry, titled “Effect of oil pulling on halitosis and microorganisms causing halitosis: a randomized controlled pilot trial,” researchers found that oil pulling reduced plaque and bad breath associated with mouth bacteria.
In 2009 a study published in the Indian Journal of Dental Research reported that, “oil pulling therapy showed a reduction in the plaque index, modified gingival scores, and total colony count of aerobic microorganisms in the plaque of adolescents with plaque-induced gingivitis.”
Full article: http://healthimpactnews.com/2013/oil-pulling-goes-mainstream-health-benefits-cannot-be-denied