Would setting yourself up a little spreadsheet (computer type - not the earthing kit type) or something akin to a pain journal help? You might include the weather for each entry, including your local relative humidity. I ask that because weather & humidity have an effect on electrical fields and the static contained in your body (like ststic shocks being more common in cold dry weather than humid summers).

I heard about earthing some months ago before I heard about NT. Gotta admit I'm more than a little skeptable (like with that Rebuilder gizmo), OTOH, I'd never discount the placebo effect - I'm all for it if/when it works.

Doc