I love that one as well. I think it's much more likely that an everlasting gobstopper will be invented than NNVC ever earning one penny.
My only regret is associating a great character like Willy Wonka, who had great business acumen, with a charlatan like Diwan. One may say Willy Wonka is a fictional character, but NNVC's fantasy 'cides are fictional too.