TDs - as a chemist - no, I can't explain it.
That is exactly the point.
I now realise there are many things in this world that scientific theory cannot explain (just as I'm sure in the 1800s, the equivalent to the Runners World website would have had a similar debate about things that we now take for granted as 'fact' and proven.)
No, I cannot explain why it works - I also know there are so many reasons why simply saying it is a placebo effect is insufficient (albeit, I strongly believe that 'belief' and convincing all aspects of your mind (and body and soul), is a huge step in the recovery process.)
Trust me, 20 yrs ago, I was exactly where you are now - everything had to have an explanation, everything had to be evidence based and 'factual'. As I go through life, I realise there is so much none of us can explain.
Good luck anyway, whether you choose to deny, or choose to believe - either way you can be 'right'.