This washing powder recipe was one of the first DIY products I made, I was looking for a product that wouldn't flair up my daughter's excema, she has super sensitive skin which reacts badly to store bought washing powder/liquid.
Once I made the switch to this powder, her skin cleared up and she wasn't itching all day long.
This is a thermomix recipe but you could easily adjust by buying soap flakes and then milling your salt in a blender, then stir it all in a large tub.
You can also add a cup or borax to help give it even more of a boost.
Play around with scents, I like
Lavender & Geranium (great for the skin)
On Guard ( great for stopping germs & bugs)
Lemon & Wild Orange
Lemongrass ( this is my favorite for adding to vinegar for the fabric softer)
You can also double this recipe easily to get a couple of months out of it.