I wash them only. There is a balance to be found between exposure to too much bacteria etc, and the need to maintain a floral balance in healthy bodies
Todays newspaper here in SA carries a study which says that cattle and horse farmers have been shown to have a lower incidence of cancer than the general population.
Exposure to the bacteria in cattle and horse dung has strengthened their immune systems to better deal with cancer
In this, as an all things, balance seems to be the key
We wash and clean our birds food, but in the wild they eat their food as it is, then go to salt licks in the forest and eat the salty earth