To use soapnuts as a natural laundry detergent, put 5-10 soapberry shells in the small cotton washing pouch and tie it closed. Then simply pop the pouch in your washing machine with your laundry and run as normal.
The hot (or warm) water enters the cotton pouch and releases the saponin (soap) from the soapberry shells within the bag, that then spreads out in the machine and naturally washes your clothes.
If you wash your clothes with cold water, you will have to soak the soapberries in the pouch in hot water beforehand for several minutes and pour soapberries with the water in the washing machine. That is to help them release the soap and make them work as a laundry detergent.
You can use the same shells 3-5 times, or until they become thin and lose their colour which is when you can recycle them in the compost. Brilliant!