I have rescued seeds from bought pumpkins to plant next year. The problem seems to be getting the orange pulp off the seeds without making them germinate by prolonged wetting. I had butternut squash seeds that went mouldy in days because I didn`t get all the pulp off. Thankfully I have more squashes so I can try again. I also have seed left out for days to dry properly too.
I believe that the maturity and ripeness of the donor fruit and hence the seeds will determine wether or not the seeds will germinate next spring. I am trying to harvest seeds from several fruits to increase my chances of getting productive seed.
Col.