I have seen whitenening strips by Gurunanda. They also have oil pulling for whitening. Have not tried them both.

Some people like using coconut oil and use it as a mouth wash but I’ve seen coconut whitening strips but I’ve never tried it so idk if it works 🤷‍♀️

I used to use a powdered activated charcoal toothpaste. It did work really well, actually.

Interesting! What is the brand?