Washing soda is a substance also known as sodium bicarbonate. While it's sometimes referred to as baking soda, it's a completely different substance. Washing soda is typically used as an alternative to traditional washing powder, especially for those with allergies or reactions to commercially produced soap. Alternatives to washing soda allow you to make washing powder at home, without having to track down this hard-to-find ingredient.
Make your own washing soda and washing powder using baking soda in place of the washing soda. Grate a full size bar of soap with an old cheese grater. Pour the grated soap into a large metal pot and fill with enough water to completely cover the soap. Place the pot on a low heat and stir with a wooden spoon, until the soap melts into the water. Dump the soap and water mixture into a large plastic bucket and add 2 gallons of hot water. Mix the ingredients together and add 2 cups of baking soda, mixing again. Use 1/2 cup to 1 cup of the mixture to clean your clothes.
Borax is a powdered material that is similar to washing soda. Make your own version of washing soda or washing powder by grating bars of soap until you have 8 cups of soap shavings. Pour the shavings into a pot, top with warm water and boil over a low heat. Pour the mixture into a plastic container and add 8 cups baking soda and 12 cups borax. Stir the mixture with a wooden spoon, until it's well mixed. Use 1/2 cup of the mixture per load of laundry.
Distilled white vinegar will leave your clothing with a light and fresh scent. Pour 1/4 liquid Castile soap into a plastic bucket and add 2 cups baking soda and 1 cup distilled white vinegar. Continue stirring the mixture until the vinegar is distributed through and the mixture begins resembling soap flakes. Use 1/2 cup of the mixture with your laundry.
When making your own washing soda or washing powder, store the finished mixture in a plastic container with a snap-on lid. Place a wooden spoon inside the storage container. Before using the powder, stir the ingredients carefully with the spoon, making sure that the ingredients are well combined.