[header] How to groom a cockatiel [title] Provide a small dish for the bird to clean itself. [step] Birds often enjoy bathing themselves and keeping clean. Offer your bird a small dish or bowl filled halfway with lukewarm, chlorine-free, filtered water. 
Use a ceramic bowl; the heavier weight will prevent the bird from spilling it or knocking it about. Remove and clean the dish when the cockatiel has completed its grooming routine.