How often should you clean an olive oil dispenser?

This depends a bit on whether you’re using the same olive oil each time or if you switch between different brands/origins for your olive oil. If you’re switching types, clean your dispenser. If you’re using the same type of oil, just make sure to sniff it between uses. If it smells like fresh, aromatic olive oil, you’re fine. If it’s smelling a little rancid, it’s time for a cleaning.