Once upon a time, a long long time ago, there was a song called "Tell Her No" by the Zombies. See the video at the bottom.
I like to play it sometimes in the courses.
Here is the YouTube link: http://www.youtube.com/watch?v=6cYdH46HqpE
A simple and stylish song. With quite a message.
I like to let the music tell the message. I think it reaches a different place than my mere words. Some of the guys just want to think, and some get annoyed a bit, but that's ok.
And I like to make the attendees in the course practice saying "No" to some "big, bad" manager. Whom I pick out from the attendees.
I also strongly try to get this message across: "The team must explain the consequences of technical debt to the product owner. The product owner has to use good business judgment in listening and questioning."
We've all lied. But it's better to tell the truth. As your mother explained....because there's less to remember. God, it takes courage sometimes.
I recommend "The Power of a Positive No" by William Ury. (He co-wrote "Getting To Yes", which you probably read.) If you never say "No", the "yes" starts to be meaningless.