I struggle with the idea if using a clay product and not being able to see when it's dirty, I'm open to being convinced but with traditional white clay it's very apparent when it's dirty and needs changing.
Clay Cloths can use Soapy water as lubricant as well - clay cloths are rinsed in warm water during the claying process and this removes contaminants from the surface. No kneading in required like a clay bar and far quicker. You don't have to see the clay dirty to know you're removing contaminants - the feel of the paint will tell you that!