Rice hulls are added to the mash to allow for easier sparging of beers with a high percentage
of husk-less grain. Wheat beers, Rye beers etc. These grains can be "gummy" anyway, add to
that the fact that they have no husk with which to build up a filter bed in the mash, and a stuck run-off
becomes increasingly likely as the percentage of these grains increase. Save yourself some head-ache
and throw in some rice hulls.