Day 3: Brightening White Laundry (fail).

Pinterest pin and website link.

I have a few white clothing items that are embarrassingly dingy, faded, have pit stains, etc.  I love the way they fit, however, so I thought I would try a pin about removing stains / brightening whites using ingredients I already had in the house.  The pinned article said to use hydrogen peroxide, vinegar OR baking soda.  I chose baking soda because it was already in my laundry room -- and per the article instructions, I added laundry detergent, placed the machine on the hot water setting and included 1/2 cup of baking soda.  The end result was a total fail -- my before and after pictures look exactly the same, and although I'm embarrassed to admit I recently wore this sweater, I'll post the picture of the prominent pit stain taken after washing with baking soda.  What do you think -- is it worth it to try the hydrogen peroxide and vinegar treatments before tossing this sweater?

UPDATE: I tried washing the sweater two more times -- once with 1/2 cup of hydrogen peroxide {+ laundry detergent & hot water} and once with 1/2 cup of vinegar {+ laundry detergent & hot water}.  Both attempts failed.  I think this sweater is a lost cause!