What about hairspray or hand lotion?
If you apply hairspray or cosmetics, please do so BEFORE inserting the Eargo devices. Otherwise, they could clog the microphone. Likewise, if you apply hand lotion, please do so AFTER the devices have been inserted, so the lotion does not clog the microphone.
Keywords: cosmetics, clog, microphone, hand lotion
Source: User Guide
User Guide Part #: LBL0018