There's one guy on youtube who claims Bach's squiggles underneath each piece title in the original WTC manuscript actually represents an ideal tuning system for that piece.

I thought that was a crackpot theory, but then he played some pieces in their respective individual tuning systems on a harpsichord, and they sounded absolutely amazing, better than well tempered (or equal obviously). So who knows!

Bach seems to attract all sorts of bizarre numerology, alas.

I agree, but when it actually works.... shrug

Well, The Bible Code "works" too.