PS: I feel compelled to share her best advice re oral hygiene:
"You only need to floss the teeth you want to keep."
Flossing daily was the single thing that imroved my dental hygiene more than anything else. Brushing, mouthwash, fluoride treatment, gum laser treatment, regular dentist visits, nothing worked. Still had bleeding gum, pain here and there, bad smell, unstopabble tooth decay.
In my mid 20-s I started flossing daily (even multiple times when I feel like food is stuck). Really my mouth problems all went away.
I wish someone had shown me in an earlier age the benefits. I would have saved a lot of my teeth.
Ultimately, whatever you're using, I think the important part is that you're doing it daily, and being thorough.
But I still haven't actually used it for cleaning what it's supposed to. :D
(I can't speak to plaque because I can't really measure it myself. But dentists seem to think I'm flossing quite well now. ha.)
I get so much more food junk out of my teeth with the waterpik. Floss never has and still never does remove much of it - even flossing, mouthwashing, and waiting until morning to try the waterpik consistently finds junk that isn't there if I waterpik. I still keep floss handy for getting truly wedged stuff out (it can provide much more force), but it's worthless for me otherwise.
Start out with a cheap one, and start both gentle and pointed across your teeth, not into your gums. It can be much too harsh when you start out. And very clearly mouths vary a lot, so if it doesn't work, it doesn't work - hence, start cheap.
One thing I wish I learned earlier on in life - flossing isn't to pull out chunks of food from in between the teeth (although it can do this too) - if you're flossing correctly you're breaking up biofilms formed by bacteria at the gumline.
My gums had been bleeding enough during brushing that I decided to break my 14 year run without a dentist visit and get things checked out, but felt shame about the state of things, so I gave myself a month or two of runway - and adopted a daily flossing and mouthwash routine.
By the time I got to the dentist, my gums were in good shape. They removed lot of plaque, but underneath, my teeth were pristine. In the 14 years since I'd been to the dentist, either the tools had become much more humane, or I just happened to be surrounded by sadists in the late 90s/early 2000s.
Upgrading to an electric toothbrush was another revelation, and I also learned that a tongue scraper is the solution to tonsil stones.
Genetics play a part, for sure, but flossing daily has been a total game changer.
My gums were always bad so I thought I needed to floss more. But once I started using an electronic tooth brush all my gum problems are gone.
eg Oral B Glide tests at 248,900 ppm / 25% of volume for PFAS