I often use it for color, not white, but green and pink and purple. I have a huge bag of white, I've never tried it to whiten a soap. I wonder how it would hold up against a discoloring fragrance oil? It does change the feel of the soap and can affect how your skin feels after using it.
It gives bars nice slip and shine.
Kaolin may whiten the base slightly, however, it will give more subtle white look, sort of creamy. I use it together with TD. It will crackle sometimes just as TD does, sadly.
I also use pink, olive, yellow and bentonite. I like the natural colours it gives to the soap.
I sort of didn't believe in all the promises about how it will do this or that to the skin. But I have to say, it does something funky and my skin feels cleaner but softer and less dry at the same time.
I love it!
I have such a hard time understanding clay, almost all of it does nothing except dry my skin out something terrible. White kaolin is ok in salt bars, I don't notice it being drying but I also don't notice it contributing anything to the bar/lather/skin feel.
I keep wanting to use pink clay in a bar because the colour is so pretty but I don't know if it will legitimately do anything else. Pink Clay is supposed to be good for dry skin, but will it make such a huge difference from my current bar? Some additives seem really cool, but sometimes I feel like it's additives for the sake of additives. If you have 5 soaps, all the same base but with 5 different clays will the effects of the soap be THAT different between all 5 bars?