Spoken as only a flight surgeon could. I find that the more rolls I do and the more often, the less dizzy I get. I think your brain learns to "filter" the signals from the 3 semicircular canals during a movement it just gets used to. It almost certainly helps, too, if you can position your head so that you only excite one axis, or two, rather than all 3. Graveyard spiral while recovering from a 30 degree dive pass seems to come to mind.
Some of the folks in my dojo say that hopping up and down quickly after a series of rolls dissipates the dizziness. don't know if that works or why, but there's a lot of hopping going on around here!