Buying books in Germany last week, I found, when I unpacked them, that 5 free sunflower seeds were included (symbolic?) so I put them (the seeds) in a plastic pot with water and damp rags inside a plastic bag in the airing cupboard, as I do with all seeds. Two days later they are putting out big fat roots.
I don't like to take any trouble with seeds that are not viable. If they put out roots I plant them in pots with compost, and if they don't, I don't.