I like this product: https://www.amazon.com/Eucryl-Toothpowder-Original-Powerful-Removal/dp/B001ECQRU0
I don’t use it every week, at most once a month, but it really helps. It was once marketed as a “smoker’s product” but has since been relabeled. I use it although I don’t smoke, but my mom who smokes also uses it, and we both love it. It’s not a one-time treatment and is not permanent, but it’s super cheap.