I imagine that some of the non-scripted 'ad-lib' lines might be passed between productions as suggestions, because I heard the "little German" line in a production in Australia many years ago. (When the audience member responded that yes, he did have a little German in him, the Emcee said "Would you like a little more?"
The other ad libs that I remember:
To another audience member - "Do you like sandwiches? [Yes] Then maybe you, your friend and I can make one after the show!"
To the balcony, with a mournful wave - "Hello, poor people!"