If you have a load of really, really dirty clothes—for example, clothes you’ve worn hiking or gardening—add a quarter cup of washing soda, poured right on top of your clothes, to boost the cleaning power of the wash. The washing soda, or sodium carbonate (often sold in grocery stores—although it’s not food safe), softens the water, allowing the detergent both to remove dirt from your textiles and keep the soil in the water, rather than redepositing it on the clothes.
