A peroxide mouth wash can help whiten the teeth. But only do this occasionally as there are lots of conflicting reports on the healthiness of such activities. This is a useful read
Mouthwash Mix: 1 part hydrogen peroxide mixed with 1 part water. Rinse mouth, then spit out. Discard and left over solution or use it as extra solution.
Read more about peroxide HERE
This is an interesting read. DIY tooth whitening from Colgate http://www.colgate.com/en/us/oc/oral-health/cosmetic-dentistry/teeth-whitening/article/how-to-make-your-own-teeth-whitening-paste-0315
An introduction to some of the stuff you need to make the above
Be aware of the risks of listening to someone who
a) doesn’t have any training in this field,
b) most of what they know comes from Google,
That’s me I mean.
I am telling you of my own experiences for your information only. You should do a lot more research before proceeding.