Yes, too much water on the beans can lead to water gathering on the burrs, which can lead to rust on the burrs. I use the teaspoon method (just the handle), co

Yes, too much water on the beans can lead to water gathering on the burrs, which can lead to rust on the burrs. I use the teaspoon method (just the handle), cover it in water and stir the beans a couple of times. Just a single data point, but I've done this for 2 years at ~2.5 shots a day with no sign of rust on the burrs. YMMV