yea, agar and jars, not petri dishes, they are too thin, and wont allow the room for growth upwards. it needs to be completely sterile, and i have heard of some mixtures with agar and banana skins, there is a thread somewhere on how to make it. straight agar wont be enough. the reason it needs to be completely sterile process is certain fungus and bacterium can get in and destroy the seeds (which as you know are almost microscopic). im not even sure you would need the fungus in there too. but im still not sure about this.....

heres an idea, save half the seeds, and if your experiment goes awry, take the other half to a local lab or a member of the local OS who grows from seed. i wouldnt use all of them.