In your location, there are three passiflora species that are hardy---incarnata, caerulea, and lutea. I've never seen lutea, but have the idea in my head that their fruit is very small. If the shriveled pods are about the size of an egg, it's most like incarnata.

Incarnata requires a cold period to germinate, so you need to either sow them outdoors now, ot sow them in trays and pop them into the fridge for a couple of months. Incarnata self-sows pretty readily around here, but it's lovely enough that I don't mind. I DO dig several plants out of my beds every spring and pass them along to others.

I don't know if incarnata is self-fertile, but I suspect it is. Nor can I advise you re a 'sink test'---my best advice is to plant them outside and just see what happens come spring.

Oh, and re the 'invasive exotic species' question---most passiflora species are frost-tender and can't survive Zone 7 winters.

I think what Judith meant is that most exotic passion flowers are frost tender. Incarnata and lutea are both natives to the US (I don't know about Caerulea).

As far as I know there is no easy test to check if seed is viable, other than just planting.
~Chills