I spoon reared our sulphur crested cockatoo and to stop her biting I would just gently hold her beak and move her head from side to side, telling her not to bite. She hasn't in 35 years.
Don't know about your birds, Melinda, but our cocky usually only copies me, and the dogs. Our neighbor tried to teach her to swear but she didn't copy him .
They make lovely effectionate pets I find.