Geoff, where are you? This your field of expertise.
Magnetic fields obviously effect the "field" immediately in its "range". Have a look at the magnetic fields working on ion particles on the North and South poles. So it is possible to "condense" the field of flow at a particular area to enhance it's effect on that area, which will effect everything downstream of it (and possibly the reverse as well).
I would conclude it's effect to be an enhancer of the signal, much like the "sharpness" tag in Adobe Photoshop.
Clever to be sure, but the price is steep for the technology. It would ne interesting if someone was able to place low strength magnets in a "dishrag", so they don't move about, and see if it had the same effect.