A new study shows that MRI magnets can make your inner ear goo slosh around, affecting your balance and sometimes making your eyes whirl around like Pinkie Pie’s. (OK, not that bad.)
So no, you and your relatives weren’t imagining that. Generally it takes pretty powerful fields, though, so not every MRI will probably cause you a problem.
It wouldn’t work so much with water, unless you had a whole lot of ions in the water for the magnets to do funky stuff with. If MRI’s weren’t so expensive to run, I suppose one could play… er, run interesting experiments with various fluids.