You should never consume baking soda in an attempt to pass a drug test. This is a complete myth, and has been known to cause death in some instances. Here's why.
For years, drug users have been trying to find ways to cheat the system. In their desperation, they'll try anything to not be exposed as a drug user, and consuming baking soda is another one of those desperate measures.
Unfortunately for drug users, this method has no effect on the outcome of a drug test. The theory is that baking soda will help to remove any toxins from the body that would provide a positive drug test.
In reality, the removal of toxins from the body is a much more complicated system than simply trying to flush them out like you would with a blocked drain.
How to pass a drug test
In truth, the only guaranteed way to pass a drug test is to not take drugs in the first place. This is an answer that's not very popular within the drug taking community, but it's the reality of the situation.
If you've got a drug problem, you should seek advice from your doctor. Don't waste your time, money, and health trying things like consuming baking soda. It won't work, and you could end up in an even worse situation; dead.