There are a lot of home remedies for teeth that can actually do more damage to the tooth than the benefit of the whitening, causing serious problems and long term damage. Do research before starting anything and check with your dentist.

At a dental conference I went to once, a dental group introduced extra virgin olive oil (e.v.o.o.) on a cloth, applying and rubbing the tooth/teeth. I have never tried it but some patients swore by it for some kinds of staining (such as tea,coffee, and some tobacco stains). This does not affect the enamel like some other things do and can't hurt trying.

These are the things to be careful of when looking for home remedies: Many of the suggested fruits (strawberries, lemon juice) destroy enamel due to their acid nature and are not recommended. A toothpaste with baking soda or added to the toothbrush will polished teeth to help to get rid of plaque and some surface stains, but can cause tooth and gum sensitivity over time, and can affect enamel if used too much. Hydrogen peroxide kills good bacteria in the mouth, increasing the risk of gum disease. Many toothpastes combine the effects of hydrogen peroxide and baking soda that can be helpful as they are in safer amounts, but can still cause sensitivity so to watch for this but can be a good choice. There are a lot safe whitening toothpastes and products in the store now with good results, but anytime you apply something to the surface of the tooth it might cause sensitivity.

Can try the e.v.o.o., or an over the counter whitening product in the store, but definitely check with your dentist.