Yes they change color to be a brickish color and there are a couple of granules of coal-looking chunks in the bottom when you run the bath without feet in it, but when you run the bath with feet in it more stuff happens. If the feet are attached to a highly toxic body, the water at the end of the bath is gunky, thick, full of muck and coal-like nuggets. However if the body is clean like mine became after 14+ ionic footbaths then by the end of the 30 minute session the composition of the water appears to be about the same as if there had been no feet in it. I personally got over a pound of the black coal nugget type granules in my first few footbaths so I am 100% sure that the footbaths work in addition to the weight I felt lifting off of me after each bath. Now I am just normal and healthy so I don't feel such a dramatic effect. I do the baths once a month now for maintenence, but when I first started them I needed them every day for two weeks because my body was so toxic. I can feel internally when I need to use the footbath for cleansing and it is rare now since I have become so much cleaner thanks to this technology. I love it and am so grateful that it was invented because I don't know how far I would have gotten with my mercury and metal detox without it. I am sure I would not have progressed so quickly.
I was just at a healthcare convention recently where the $1400 ionic cleanse footbath machines by All Health Seekers were being demonstrated. They had about 4 baths going at once with 4 different people's feet in each. Each person's footbath had a unique color to it. Additionally, the demonstrators had a row of used footbaths lined up to be disposed of and each had a unique color, density, flecks, bubbles, etc. This footbath draws different things out of different people's bodies depending if they are smokers, and depending on where they are most toxic like in the liver, gallbladder, etc. Similarly, my husband and I had completely different looking footbath water at the end of our at-home treatments. He was far healthier than I and had zero mercury toxicity and he had only a couple coal-like-nuggets at the bottom of his bath as compared to my thousands.
The bottom line is that this footbath technology helps de-acidify the body by adjusting the PH to be alkaline. Cancer and many other diseases and parasites
cannot live in an alkiline environment. So even if you don't believe that it draws out impurities, than at least it alkalinizes the body.