When you said, "Many dentists are scoundrels" - You got that right! When our daughter was a teenager we took her to a new dentist in town. After examining our daughter's teeth, he said she had 5 cavities. She went back and got 2 filled but never did anything about the other 3, reason being that we moved away. The next time she went to a different dentist she was told that she didn't have any cavities.
Our son has never had a filling, never had a cavity. They inherit their teeth from their mother. In the almost 40 years that we have been married, she has never needed a filling! Yet she has fillings in her mouth. I strongly suspect that the reason she has these filling is because she was a foster child cared for by the State and so whatever dentist treated her drilled holes in her perfectly good teeth and the State paid for it.
Just started oil pulling this week. So far notice nothing worth mentioning but are encouraged by all the postings here on the subject.