They should have the chance to bathe at least once a week. Put a couple of lettuce leaves in a bird bath with only a little water in it, to get your budgie started. Damp lettuce leaves without any more water at the bottom can also provide a super wash and brush up, for a bird that hasn't got the hang of a bath yet. Or try a spray of lukewarm water from a plant mister. Always dry cage after a bath. In winter, the budgie can be very gently blown dry with a low heat setting drier kept at a safe distance so only a warm zephyr touches the bird. Damp kills.
