baking soda and me

hey guys ive been using baking soda for the past few days to help whiten my teeth.

this is how i do it

first i brush my teeth with regular toothpaste then i wait 30mins+ then i get a small cup and poor some arm and hammer baking soda into it then add a very little water to form a paste like toothpaste. then i brush my teeth with it for like 2-3 mins. i do this once or twice a day am i doing this right? am i missing anything? if so lemme know so i can go get it. thanks in advance

[Jerome Tsang, DDS]

I've never heard of using baking soda for tooth whitening purposes.  I do believe Arm and Hammer sells toothpaste but I'm not sure if there's baking soda in it.