I am sure I will be shot down in flames by "bio-detox fans" but have to say I, personally think it is a load of old twat.
The element of the machine interacts with the normal sweats etc of the foot and it is purely a chemical reaction between H2O, the element and the salts from the feet.
I have to say that IMO it's "therapies" like this that give holistic health a bad name.
Let's all wise up folks!!
p.s if you have bad circulation a normal bog standard "foot spa" would be just as effective.