I started swishing or oil pulling a few months ago. I get the best results (as far as teeth cleaning and whitening) with a mouthwash I bought at Vitamin World. It is made by Herbal Authority and it is called Tea Tree Oil Mouthwash. Advertised as oil from an Australian tree. It does have a spearmint additive and some other chemicals added to the solution. I am not for sure it the others are naturally occurring or not.
I only swish with it like true mouthwash (30 seconds) it cleans my teeth better than anything I have ever tried in my life.