What’s the best way to move money between two bank accounts using cryptocurrency as an intermediate token, ideally at near-zero cost?

Ripple and Stellar are both designed explicitly for this purpose. Hand-in-glove-fit.

So Joel Yarbrough cites it well.

One really doesn't need a cryptocurrency to move money between banks. Once you learn how money really moves, it is all about consensus and honoring the IOUs that have been issued.

You could issue token using Hyperledger, even. However, in all fairness, Ripple comes out on top, Stellar still has some teething and directional (read: survival) issues.