A museum volunteer in Tucson asked me why I wash every sherd, and I actually had to think about it
She said washing removes residue that could tell us about what was stored in the pot, and I had been scrubbing artifacts clean for 3 years without a second thought. Now I only rinse when the dirt is hiding decoration, and we pulled grain residue off a Hohokam bowl last week that tested positive for amaranth. Anyone else change their field methods after one casual chat?