Both of these are not good responses and are easily discounted by most people ("I don't take nude photos"/"I never tell anyone my pin").
Average people see zero equivalence between sending nudes or their bank pin to a specific stranger and Google keeping a record of every website they've ever visited.
Surely the "I never tell anyone my pin" is just an admission that they do have something to hide?
The point is that there are many things that should be kept private/secret and often the need for that secrecy isn't obvious to people who have never been in particular situations. A woman trying to escape from an abusive relationship may need to keep her location secret to avoid being murdered by her ex, but your typical white male who declares "nothing to hide" may have difficulty in understanding that, whereas they may be able to grasp why their PIN should be kept secret.
I understand the point, but you're taking their statement "I have nothing to hide" way too literally, and these sorts of arguments based on literal interpretations rarely convince anyone. Has anyone actually ever been convinced to take privacy more seriously by this "insight"?
It's not so much a method to convince people to take privacy more seriously, but demonstrating that people who say "I have nothing to hide" haven't really thought about it and how it's such a ridiculous statement.
My aim would be to get people to understand that everyone has stuff that should be kept secret and that it varies according to their circumstances.