Yesterday, the Guardian's Ethical Living blog posted a pre-Q&A article for Neal's Yard Remedies.  Neal's Yard Remedies sells various essential oils, herbal remedies, homeopathic concoctions, and so forth.  The Guardian asked people to post their questions in the comments, and promised that the folks at Neal's Yard Remedies would respond.

The comments thread immediately went hilariously left of field.  My personal favorite is, "I've been soaking a £20 note in a bathfull of water for the last few days, is it ok to pay for an order using my new homeopathic money? I now seem to have rather a lot of it."

None of this will turn the minds of the zealots, but this is an excellent learning opportunity for people who are on the fence about non-Western medicine.  Certainly there is a great deal of non-Western medicine which is helpful, or at least does no harm.  Acupuncture for example has been clinically shown to be effective in proper double-blind studies.  However, it behooves us to retain some skepticism about things like homeopathy and herbal remedies which promise to "purge toxins."  There is plenty of harm being done by these - to your wallet. 

One of my favorite examples is the little pads you put on your feet to "purge toxins."  The pads turn brown, ostensibly with all of the collected toxins.  However, the pads are made of a substance which turns brown when it is exposed to air.  The same goes for ionic detox foot baths, which noted debunker Ben Goldacre has shown are simply using electrolysis to turn the water rusty.

Many people do not trust experts, and think that the term "scientists" is a slur.  That's okay!  Do this: If you have an ionic foot bath, simply turn it on without placing your feet inside.  If you have some of the little foot pads, open up their package and leave them on your counter overnight.  See what happens.

Of course, this is a simple experiment - technically, it's neither single-blind nor double-blind.  The heart of Real Science is the double-blind test.  This is a test in which neither the subject nor the experimenter knows which is which.  The results of a double-blind test are effectively unassailable, barring any kind of deliberate cheating.

Let's say that you have a bottle of homeopathic remedy which you use with some frequency.  For a single-blind test, get two identical bottles and label them A and B.  Have your spouse pour the homeopathic remedy into one bottle, and fill the other with tap water.  Alternate using bottle A and B, and record your results (does it seem to work or not?)

If you want to really be sure of the results, do a double-blind test.  You will need a third person: let's say your best friend.  Give your friend two identical bottles, labeled A and B.  Ask her to pour the homeopathic remedy into one, and tap water into the other.  Then give the two bottles to your spouse to dispense. 

Every day, your spouse will give you one of the bottles to use, without telling you whether it's bottle A or B.  (What makes this a double-blind test is that your spouse doesn't know which bottle contains the homeopathic remedy, and you yourself don't know if you're using bottle A or B.  You are both "blind.")  At the end of the day, report back your results - did it seem to work, or not?  After a little while (depending on how often you use it), tally up the results for bottles A and B.  Then ask your friend to tell you which bottle held the homeopathic remedy, and which the tapwater.

After you've finished your test, you will want to mail the results to the homeopathic manufacturer and request a refund.  Don't think so?  By all means, prove me wrong!