Thanks a lot!
So, the experiment in the article says glass jars were used; Greg, if I understand well, advices the use of paper bags; ohers say to use ziplock bags with a piece of paper inside.
I guess the fridge makes the difference, also.
I don't know how many seeds I will get (I'm waiting for seeds from the AHS and their program for non-US residents), if they are enough I may try different methods. I'm planning to plant some right away, but unless I riarrange the garden quickly or find good big pots I won't be able to plant them all together.