I do mine in the pressure cooker which seems to help (we have pretty hard water) but a pinch of baking soda helps soften the water too. (rickiheller.com)
The raw materials used in the product are 100 % naturally derived cleaning ingredients from renewable sources, have natural fragrance extracts and use naturally softened water. (thefashionablehousewife.com)
The baking soda helps to soften the water so your detergent works better. (wonderfulandwild.com)