I've never heard of using bleach, first of all. What that person (mac_daddy) said was probably a joke.
I have heard from other tweekers that baking soda does indeed work. One person I knew said that he always took a bottle of orange juice with two heaping tablespoons of baking soda mixed into it with him when he went to work crew (work duties assigned by the DOC as an alternative to jail time) in case they decided to give him a UA. He said that this always worked too.
Here's what someone else told me to use as the recipe:
Take 2 heaping tablespoons of baking soda and mix into a glass of water. Drink it about 2-3 hours or so before you will have to pee along with however much more water afterwards that end up totaling about 40-50 oz.. The important part is that after you drink the baking soda along with the 40-50 oz. of total fluid (water), you will need to pee once, then the next pee after that will be clean. I'm sure that you could drink some water after the first pee in order to give you enough fluids to be able to pee the second time.
The baking soda will neutralize the PH level in your pee which is how this method works. I don't know what effect the orange juice has in the equation and I honestly don't know if it even plays an important role in producing the clean UA. I used meth for years and luckily never had to take a UA and test this method, but this is understandably a hot topic in the tweeker community and I've heard this from several tweekers who have claimed to have used it successfully.
A friend of mine said that he saw a girl do a hit of dope the same day as her UA and used the second method (no OJ) and produced a clean UA. Good luck!
P.S. I just realized that stewyb copied and pasted my recipe from a previous post that I made (which is partially what I did but added the part about the OJ)