Reducing Jupiter's radiation belts

Just like the [[water]] geysered out by [[Saturn]]'s [[moon]] [[Enceladus]] weakens Saturn's [[magnetosphere]] by a factor 10, it would be possible to dramatically reduce [[Jupiter]]'s magnetosphere (and thus radiation belts) by placing something icy in an orbit around Jupiter that tides it to geyser a lot of water too. That would reduce the radiation around Jupiter, helping the colonization of Jupiter's moons. It is even possible that the reduced radiation and magnetism, in combination with an already far distance from the Sun, would allow its moons to retain [[artificial atmospheres]] despite [[lower gravity than on Earth]].