I've tried OP on a Water Fast before. It seemed like a good idea since your body is both removing toxins and getting healthy EFT's while you're fasting (I was pulling with Flax Seed Oil).
I also wanted to see if the absorbed oil decreased my headaches. Overall the only major effect I noticed was that it seemed to trigger the hunger effect big time.
The hunger thing is also why I don't do well on juice fasts. With water by itself I've noticed it's easier to not feel hunger. Juices and oils just seem to signal that it's feeding time again.
As for the other poster recommending fluoride, I'd love to see the studies that conclude that fluoride helps strengthen teeth. The only thing I understand is clear about the effect of fluoride on teeth is that it weakens tooth enamel. Fluoride is a toxic gas, not an organic compound that provides any nourishment to the body.
And finally to answer your original question - take it easy! As Molly likes to point out - it's not an Olympic event. Just gently suck the oil through your teeth (swish it) at a comfortable rate. And Molly should know - she lives in San Fran where swishing is something of a religion.
(just to get her attention since she's been away for awhile)