Oil pulling has been around for donkeys years.
I am not sure it is meant to be a “cure” for anything. I think people use it more for a sense of well-being.
I believe it originated through traditional Ayurvedic medicine; it is very popular in Eastern cultures like India and China anyway.
I know a couple of Asian people who swear by its effectiveness for well-being, and also a Western lady who says it has really helped improve the health of her teeth & gums.
It is an ongoing commitment every morning and apparently takes some weeks for results to start showing. So doing it one-off and expect results would be a waste of time.
Apart from the price of the oil, the practice is free and requires no money layout. So you are hardly going to be ripped off by doing it. Although you may feel like a bit of a dill!
If you are going to do it, obviously getting reasonably good quality oil is in order. In other words, avoid Crisco and other refined oils designed for deep fat frying.
I tried it a couple of times out of sheer curiosity, but swishing (pulling) oil in my mouth made me gag. Plus I could only ever last a few minutes before my jaw would start aching.