The link which you have posted here offers great info on teeth whitening. However, our kitchen can offer several teeth whitening agents like lime, baking soda. I recently read somewhere that rubbing banana over your teeth can make your teeth look whiter and brighter. 

What I feel that using teeth whitening strips isn't bad at all as people assume. I have tried it  and it has worked for me. You must compare the good teeth whitening systems at first via online sources as I did.