I just use an old coffee grinder. Usually a quick wipe with a paper towel works for me.
Co-head cook of Smokin' Timbers BBQ
Sponsored by Big Green Egg, Oakridge BBQ, Sam's NW BBQ Co.
XL BGE, Two L BGEs, 22.5 SS Performer Blue, 22.5 Weber Kettles (Grey, Green, Brown, Red, Two Tone Red) 22.5 WSM, Three 18.5 WSMs, Mini WSM, Rib-o-lator, Green Thermapen, Stoker with wifi