I like these sort of ideas, I was also wondering if you could 'induce' water into splitting via a coil without electrodes. I think all things are understandable if you can break them down into small understable bits.
So back to basics:
Stans method is based on a very simple premise: electrostatics. Likes repel and unlikes attract.
Electrostatics rely on positive and negative charges, they are simple to understand. Water is a polar molecule ( slight positive on one end slight negative on the other due to asymmetric orbit of electrons), so placing water near to a separate entity that has a charge ( a charged balloon near a stream of water will do the job).
In electrostatics you can 'induce' a charge from one object to another. Objects commonly used in electrostatic experiments are rubber/perspex/plastic/hair, all these things are insulators.
Water without ions is an good insulator. Charged objects get their 'charge' from lack of or excess of electrons ( free electrons I guess), ones that can move around from atom to atom.
Positive charge is lack of electrons, negative charge is excess electrons.
Water molecules in a magnetic field will align themselves to the field ( minimum field strength I'm not sure), so you might be aligning the water molecules i.e. getting them to point in a given direction depending on the north/south of the field. But I dont think you are stressing the bonds, just getting them to align with the mag field.
To stress the bonds you still need some electrostatic field ( electric field same thing)
So you still need an area where the water is immersed inbetween an area where negative charges are on one side and positive charges are on the other side.
I can certainly see what your thinking with this experiment, I've spent some time thinking along the same lines but have been unable to come up with an alternative to electrodes ( stainless tubes etc).
Kelvins water dropper comes to mind where water is charged when it splits into water droplets, the mechanism where a water stream breaking into droplets and the droplets acquire a charge I dont think is well understood. But it may be the atmospheres electric field ( 100v/m) plays a role. Once again its electrostatic in nature, probably surface charge on the water surface of the droplets. Somewhat different to water acting as a capacitor, probably related in some way.
Summary: I have no answer to the problem