1. Mix the citric acid, washing soda, baking soda, and sea salt. Combine 1 ½ cups (355.5 g) of citric acid, 1 ½ cups (355.5 g) of washing soda, ½ cup (209 g) of baking soda, and ½ cup (130 g) of sea salt in a large bowl or pot. Stir the mixture so all of the ingredients are well combined.