There is no evidence that oil pulling needs to be done for at least 20 minutes to have a positive effect. In the study conducted by Dermatest, Fresh was applied for 3-5 minutes daily. The reasoning that the oil takes so long to penetrate all the gaps between the teeth has no foundation, because oil as a liquid easily penetrates all areas of the mouth at the same time. Presumably, the 20-minute recommendation comes from traditional use. If you wish to spend this amount of time oil pulling, you are welcome to do so using Fresh. Those with less time on their hands will also benefit from a 3-5 minute daily application.