People who aren’t spa-goers are probably blissfully unaware that their bodies need to be detoxified.

It makes sense that over a lifetime, chemicals that weren’t in our bodies when we were born are bound to accumulate. It’s less clear that said chemicals can be removed by processes such as the ion detox foot spa treatment.

At $45 for a 30 minute session that consists of sticking your feet in an ionized water, there had better be some good science to prove that the treatment actually works.

The premise is that when you put your feet in water ionized by a mild electric current, positive and negative ions are absorbed into your body through pores in the skin. The cells are energized by the ions, causing them to release oil, acid, fat, heavy metals and other debris and waste that have accumulated in your body.

The toxins are then carried down to your feet and expelled into the water, which turns a disgusting color ranging from bright rust to dirty brown.

Some manufacturers even provide a color chart so you can match the color to the type of toxins that have been expelled.

While thousands of Web sites claim fantastic benefits for ion detox treatments – from curing parasites and worms to treating AIDS, herpes and cancer – there is a distinct lack of scientific evidence that ionic detox foot spa treatments actually work.

There are a lot of skeptics, including Dr. Ben Goldacre, who said the water turns brown because the metal electrodes that ionize the water become rusty and release rust into the water by the time the 30 minutes are up.

Goldacre demonstrated by putting a Barbie doll in some salt water ionized by a car battery. Remarkably, Barbie’s plastic feet turned the water brown.