Does oil pulling really pulls toxins? Hard to say. How does it really work, don't know and don't care, it cheap, effective and doesn't hurt :)
Here's my experience with it in almoust 2 month with regular sunflower oil 2x per day.

1. Mucus in my nose and sinuses. Before it was full most of time, but now I hardly use tissue paper and I can breed more easily.
2. Second my vision got slightly better. I have -2 on both eyes. Since oil pulling I noticed that if I blink few times hard enough my vision is normal for a few seconds. Without oil pulling that is impossible to achieve so oil must be doing something to my eyes.
3. On some parts on my forehead dandruff is gone and inside ears is much less than before.
4. Dry and flaky lower lip! Now this one is tricky problem. Before I used to have normal and soft lips and because I have Seborrheic Dermatitis (SD) I tried with homeopathy to cure it. That was big mistake! They gave me Arsenicum album and after a week of using it my lower lip went crazy. After a while on some website I read that lower dry lip is symptom of metal toxicity and when I read definition for Arsenicum album (Arsen. alb.) is a frequently-used homeopathic  substance derived from the metallic element arsenic.  I was an lip balm addict for a year before I started oil pulling. Within month my lips got better by 40%, another month another 40% and now are almoust normal and I don't need lip balm any more!

5. If I don't do oil pulling pesticides in fruits give my nasty headaches. Even touching pesticides gives me headache but with OP that is eliminated. In fact I don't have headache at all, and before once per week was normal to me.

6. Bleeding gums are history! Before I would blame toothbrush but I was so wrong, gums were just to soft and sensitive.

7. Food doesn't stick in my mouth anymore. I can chew more easily and food just melts in my mouth!

8. My back doesn't hurt any more! Before I would blame my bed and I even bought new mattress but it didn't helped at all. With OP pain was gone within 2 weeks.

9. My hair doesn't drop off anymore and my blood pressure is normal!

As you can see my condition was pretty bad. OP clearly made my life much better.