Be patient, calm, and even excited about the words you're teaching. Keep in mind that many of out larger handfed parrots may live up to 70 years, if given a good diet and proper care. Obviously, if you don't like opera, don't teach it to your birds. A popular song or catchphrase today might be out of style tomorrow. Many a bird have been sold due to excessive use of profanity.
Profanity gets attention for the wrong reasons.
My friends in Phoenix responded to an ad for a young, handicapped African Grey. The bird was cheap because it had an incredibly obscene vocabulary. The owner's two teenaged sons had taught the bird increasingly more elaborate vulgarities. My friends didn't buy the bird, but they suggested to the owner that she change her ad to emphasize the bird's crude vocabulary. Most parrots with obscene vocabularies are not as lucky as Lucky.