Last time I used my grinder to grind up some feed I decided to flush it out with some ground hay first as it had been a while and looked like mice had been in it.
My unloader auger didn't like it much..... damaged a gear getting it apart and the one on the other end is pretty worn.
Haven't checked availability or pricing yet. No more than I use it I can probably repair /reuse what I have on the gears but will be looking into weld on auger flighting.