@PaNda Said
When I had a foot bath, one of the toxins was "heavy metal". The water was rather nasty. There were black flakes (the metal) floating around along with red ones (blood cells).
The naturopath showed me a color chart and told me the liver, bladder, lymphatic system, and kidneys would be purified. During the process, there were all sorts of colors in the water. Tobacco in my system produced a brownish color according to her chart.
I'm not convinced the results of the foot bath were accurate, though.
It makes sense to me that not eliminating waste through urination and colon cleansing will cause poisoning of the body.
The footbath, with the person showing you all the black stuff afterwards...classic scam.
https://curezone.com/forums/fm.asp?i=567466
https://www.devicewatch.org/reports/aquadetox.shtml
https://www.chem1.com/CQ/FootBathBunk.html
These links and many more, are very easy to find on Google. Just do a search for "foot bath detox scam". My search resulted in 246,000 results: https://www.google.com/search?ie=UTF-8&oe=UTF-8&sourceid=navclient&gfns=1&q=foot+bath+detox+scam
The red and black you are referring to is the result of metal corrosion due to electrolysis. I can also find black flakes in my humidifier water tank, it's the same process. The bath water changes colors whether your feet are in it or not.