Budgies love to bathe. You can purchase small birdbaths that fit into the door of a standard budgie cage. They should be filled with lukewarm water and left for the bird to enter as he chooses. Budgies can also be bathed by misting with a fine mist spray bottle. They should be bathed twice weekly to maintain healthy plumage. Wing clipping is essential for initial training; you will need to clip the bird periodically as his flight feathers grow back in.
For more information, please read How to Groom Your Budgie