Basically, i'm saying that the oil is attracting and removing non polar bacteria when its being pulled, while simultaneously stimulating saliva production in the mouth. The salivary glands start excreting some bacterias, viruses, and various biochemical compounds that are attaching themselves to the saliva and oil mixture. The saliva will be attracting the polar bacteria and chemicals.
This is why I believe that the oils that taste best(coconut oil) are going to work the best, considering they are viscous enough not to become saturated too quickly.