Fill your kitchen sink or a bathtub with very hot water, then add ¼ cup Dawn Original dish detergent and 1 cup baking soda. Swirl until the baking soda is dissolved and then add the pillowcase.
Grab a hunk of the pillowcase in each hand and rub the two bunches together, so you’re rubbing the fabric against itself. Switch to another area on the pillowcase and repeat until you’ve given it a good all-over rub.
Drain the sink, refill it with very hot water, and add a few more drops of dish soap. Let the pillowcase soak in this fresh solution for 1-2 hours, or even overnight. Then rinse it thoroughly in HOT water until it runs clear.
Put the pillowcase through a hot wash and rinse cycle in your washing machine using your regular laundry detergent and 2 cups of white vinegar in the rinse cycle—but no fabric softener.
