How I have save seeds, every year when my kids carved pumpkins I would collect the seeds and spread them out on a sheet of newspaper. I leave the seeds on there for about 2 days then some of the seeds are stuck together , I just bust them apart and put on fresh newspaper for a few weeks. I save the seeds in a large zip lock bag. I haven’t had to worry about hybrid seeds because I only have non hybrid pumpkins. When planting I put extra seeds in my hills to compensate for a few bad seeds. I would say maybe 75% or more grow. I do plant in hills, what I do is take a small handful of fertilizer and drop it on the ground and cover with a small pile of dirt, then put 4-6 seeds in it and lightly pack it. I like fertilizing this way, because I don’t fertilize the weeds that way. It takes time doing it this way but it did work good.