Stephen Barret is the last person I would trust to be an impartial reporter of quackery. Anyone in bed with big pharma has a specific agenda and direction that effectively cancels out any claim to impartial reporting.
As for the footbaths, all I can really say is that I've had them and found them beneficial. The bath did produce what I recognize as detox symptoms and I did feel better afterwards. I had no particular idea as to whether this would be true or not but for me, it was.
Also, the person who gave me the footbath said that the colors meant nothing, though it used to be thought that they did. She said about what the doctor said in one of these posts...the changes have to do with the water used, the person's skin and chemical balance, etc.