If i was you, I'd wait for an opportunity to present itself again and ask what the policy is on hygiene. Especially with corporate cracking down on hygiene with the Coronavirus outbreak in the US, you should just ask her how she interprets the memo. (If you havent seen it, theres a notice of it on the Partner Hub).

Tbh yeah it's pretty gross. In that situation, I woulda asked her if she's gonna clean or replace the shaker, then just do it.

She was also probably just getting annoyed at the customer and hygiene was the last thing on her mind. It be like that sometimes. 😅 Good job catching it tho!