Grate 1/3 of a large bar (or half a bar) of cheap bath soap (ivory, jergens, rosa venus are some of the ones I’ve used). Dissolve grated soap in 4 cups of water on LOW. After dissolving, stir into a large bucket with 1/2 cup borax 1/2 cup washing soda (NOT baking soda!) 3 gallons of water Stir until it starts to thicken
Cover tight and let sit for 24 hours before using.
Stir before using.
use 1/4 to 1/3 cup per load
Cost per load: 2 to 3 cents (compared to to almost 30 cents per load of commercial detergents)