Add 1 cup of Borax to the empty container.
Add 1/2 cup of citric acid to the empty container. If you have particularly hard water, add a full cup of citric acid.
Add 1 cup of washing soda to the empty container.
Add 1/2 cup of kosher salt to the empty container.
Place the lid on the container and shake to mix the solution.
Add a tablespoon of the citric acid solution to each load of laundry instead of commercial detergent. Fill the “Rinse Aid” with white vinegar and run the laundry machine as normal.