Current trends have suggested using apple cider vinegar as a mouthwash or rubbed on teeth to clean and whiten enamel. Most dentists feel this is the worst thing you can do to your teeth and oral tissues due to its highly acidic nature.
Activated charcoal which is an abrasive black powder has not been approved by the FDA and does not have the ADA seal of acceptance. The powder can wear enamel away and expose your inner dentin layer which is yellow in color. There has not been enough published research to prove any of the suggested claims.
Swishing with coconut oil (oil pulling) or the spice turmeric also has no scientific evidence to show it whitens enamel surfaces.
A healthier option is to brush twice a day for two minutes using a whitening toothpaste with the ADA seal of acceptance. Make sure to floss in between your teeth to remove plaque which can also pick up a stain. Avoid foods that we know can stain teeth such as dark sodas, coffee, tea, red wine and cigarette smoking.