Given that I have trouble with dumbing things down for a non-security-literate audience, I think the right solution here is for me to work at educating people -- I'm already planning on doing this, actually, by providing information about all the potential attacks which my code is designed to prevent (and which other code isn't).
That angle may work best. If you can prove to someone they have no pants on while they think they are fully clothed, that is sure to tag the amygdala, and hence attentiveness.
Given that I have trouble with dumbing things down for a non-security-literate audience, I think the right solution here is for me to work at educating people -- I'm already planning on doing this, actually, by providing information about all the potential attacks which my code is designed to prevent (and which other code isn't).