Outside of the Delaware Valley sure, people won't know where you're talking about otherwise, and quite frankly no one cares.

Within the Delaware Valley it is not unreasonable to expect people to be more familiar with the counties and townships, so you're just being intentionally vague if you say this.

If you come across another person in a different region of the world who's from the area while traveling, than it makes sense to follow your initial statement with your actual place of residence, as they'll likely have a vague idea of what you're talking about.