i got myself one of these last year. i used it on the lingual (inside) of my teeth about 3 months after my official dental cleaning. i used it once more about a week before my next appointment. super gently near the gumline, 5 mins tops

it's hilarious, the hygienist was joking about how she has nothing to do

i still think eliminating sugars and refined grains does the lion's share of the work though