Recently on a forum someone commented on how dirty/dusty rice hulls are and that they rinse them to avoid getting any of the dust and dirt into their precious beer. Then someone on another forum commented on how that dirt might carry over to cause haze. Somewhere in the back of my head the BS meter pegged out. Let’s think about this for a minute. Suppose they were extremely dirty with dust from ripping the rice out of the hull. At worst it is rice dust or hull dust and probably not dirt at all. Rice is planted in water, but it is harvested like hay or wheat. It never has any real chance to get all “dirty.” So the dust is just dust, not dirt.
Let’s assume for a minute it was dirt and it got into the mash tun. Unless the particles are aqueous they would settle to the bottom of the tun. If they were aqueous they would have to survive the vorlauf (recirculation) to even make it to the boil kettle. I doubt that would happen so they would remain in the tun draff and be discarded, but if they did make it to the boil kettle any finings would most likely bind them or they would end up as part of the break material left behind if kettle cooled or left in the fermenter if a counterflow chiller was implemented. In the fermenter the fermentation process would drop the particulates into the trub and yeast and I just cannot think of any way dust can carry over into finished beer to cause haze.
Now the only time one would use rice hulls is when they want to loosen the mash, probably when a large portion of the grist is wheat. Wheat is known to result in a nice cloudy/hazy brew, but some dust off rice hulls is not going to cause haze in finished beer. If you are one of those who believe you need to rinse hulls, rinse away. I know I never have and never will. Any dust will be trapped in the tun, fall out in the break, or be left behind in the trub.