How to Add Baking Soda to Laundry
If you want to add baking soda to your laundry to boost your detergent, place your dirty laundry into the washing machine and add the detergent as usual. Begin the wash cycle and let the machine fill completely up with water, then add 1/2 of a cup of baking soda directly into the water. Finish running the wash cycle as usual. For even fresher laundry, finish your laundry by drying the clothes outside in the fresh air if you can. Otherwise, dry your clothes as usual.
Do a pre-soak if necessary. 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. Start a load of laundry. 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. Add 1/2 cup baking soda when the machine has filled. 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. Dry the clothes outside. 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. Make a baking soda paste. Baking soda makes a great natural stain remover. It's gentle enough to use on almost any type of fabric. Mix a tablespoon of baking soda with enough water to make a thick paste. Alternatively, mix the baking soda with hydrogen peroxide or white vinegar. Baking soda paste is best used on fabrics that don't require dry cleaning. You'll have to rinse it away when you're finished, so the clothes will get wet. Baking soda paste works well to remove stains caused by oil, grease, dirt, food, and many other substances. Apply the paste to the stain. Lightly rub it into the stain. Make sure it covers the entire stained area, overlapping the edges. Allow it to sit on the stain for 15 minutes. If the stain is on sturdy clothing, you can scrub it using an old toothbrush. Scrub the baking soda into the stain to make sure it can treat all of the fibers. This method is fine to use on denim and thick cotton. Don't scrub the baking soda into delicate fabric. Silk, satin and other thin fabrics could warp when scrubbed. Rinse away the baking soda. Run it under warm running water to rinse away the baking soda along with the stain. For more delicate fabrics, you can wipe away the baking soda using a dampened cloth. Repeat the treatment if necessary. Some difficult stains require more than one treatment. Apply a second round of paste to the stain. Let it sit for 15 minutes, then rinse it away. If the stain remains, you may need to use a chemical stain remover or take the item to be professionally cleaned. Sprinkle musty clothes with baking soda. Items that are dry-clean only can be spruced up using baking soda. While it won't actually clean the clothes, it will absorb musty smells and make your clothes smell fresh. Cover the item with a light layer of baking soda, then place it in a sealed bag. You can use a flour sifter to evenly distribute the baking soda. If you'd rather not get baking soda on your clothes, pour baking soda into a clean sock. Tie off the open end of the sock. Place the sock in a bag with the baking soda and seal it. Let the baking soda sit overnight. It may take awhile for the baking soda to completely absorb the musty smell. Place the bag and baking soda in a cool, dry place to sit overnight. Air out the clothes outside. Open the bag and shake off the baking soda. Use a soft brush to remove excess baking soda if necessary. Hang up the item of clothing in the sun. Let it stay outside and blow in the breeze for a few hours to finish airing out. Repeat if necessary. Strong smells may require you to treat the clothing more than once. Repeat the process of sprinkling the item with baking soda, letting it sit, and airing out the clothing. If it still smells musty, you may need to have it professionally cleaned. 
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. Make a baking soda paste. Apply the paste to the stain. Rinse away the baking soda. Repeat the treatment if necessary. Sprinkle musty clothes with baking soda. Let the baking soda sit overnight. Air out the clothes outside. Repeat if necessary. 