Homemade soap for washing machine

The women in the village still make their own soap and they are so kind to give me some when it's ready. I haven't used any other from the shops since.

Ingredients:
25 lts water
2 kgs fat (from pig)
a handful of powder detergent
half kilo caustic soda
Everything mixed with a stick for 13 days and voilà!

The soap made to wash by hand has different quantities.