How do you bath a bird?

I have some friends who keep singing birds, the kind that they take to bird-singing contests. I do see them giving their birds a bath.

This is how they do it. They would fill a spray bottle with clean water. Then they spray the bird with water from the bottle. Usually they do this when the day is hot and there is sunshine. They would hang the bird cage somewhere where it can catch the sunshine and the bird inside can get dry easily. I think they do this once a week.