Good discussion topic! I think removing bacteria etc IS a crucial reason oil pulling works so well - and the lymphatic system seems to be key.
I have a dental school grad friend that tells me the reasons you have to do things like root canals, tooth extractions etc instead of treating infections with Antibiotics
like everywhere else in the body - is the mouth's lymphatic system. Circulation in teeth is handled by the lymphatic system and isn't up to the job of getting rid of infections.
Infections cause swelling that obstructs the circulation of the lymphatic system so drastic measures must be taken like extractions and canal drilling when they occur.
When I told her I got rid of a raging tooth infection (that the dentist said could only be cured with two root canals) just by pulling with oregano oil - she said it was impossible. Even if the infection "seemed" to be gone temporarily it was hiding somewhere and would be back in 6-9 months. I then told her this happened 3 years ago and my teeth were still good as new. Not severed from their roots and screwed back onto the gums as the dentist recommended.
My point is - the lymphatic system DOES have less circulation especially in and around the teeth, and oil pullings ability to help disinfect and lift out germs/toxins is therefore a HUGE assist for oral health. And I'm guessing is the main reason OP reverses so many cases of gum disease.
Most believe here that OP also cleanses the liver. There's disagreement about what all it does for the body, but it does SO MUCH for your oral health that there's more than enough reason to stick with it. And the direct link between oral and cardiovascular health makes it all the more worthwhile.