Summarize this article:

If you want to use baking soda as a deodorizer, it's a good idea to soak it in a baking soda solution overnight. This gives the baking soda time to really go to work getting tough smells out of your laundry. It works well for clothes, towels and other items that that are smokey, musty or sweaty.  Mix a cup of baking soda with a gallon of water. Pour it into a bucket. Add your clothes to the bucket. Give them a swirl to make sure they get completely soaked. Top them off with more water if necessary. Let them soak overnight. They'll be ready to launder the next day. Place your dirty laundry (and pre-soaked items) into the washing machine. Add detergent as usual. Begin the wash cycle so that the machine begins to fill with water. Allow it to fill completely before continuing.  If you're washing clothes that smell musty, hot water will be most effective at removing smells. Musty smells are normally caused by mold spores. Hot water will kill the spores. Cold water should be used for delicates and colorful items. Pour it straight into the filled washing machine so that it dissolves into the water. Finish running the wash cycle as usual.  For an extra-large load of laundry, you can add up to a cup of baking soda. Adding a cup of white vinegar will enhance the baking soda's deodorizing effects. This is the best way to dry clothes that previously smelled musty, smoky, or sweaty. Drying in the sun and wind will help to freshen them. Even on a cold day in winter, you can dry your clothes outside. Just choose a place that gets plenty of sun.  If you'd prefer not to dry your clothes outside, use the dryer instead. When the dry cycle is finished, smell your clothes to see whether they need to be treated again. If they come out of the dryer still smelling musty, choose a sunny day to wash them again and hang out them out to dry.

Summary:
Do a pre-soak if necessary. Start a load of laundry. Add 1/2 cup baking soda when the machine has filled. Dry the clothes outside.