Here is the result of my soaking/not soaking experiment. The seeds in the first four small pots germinated after around two weeks without any presoaking or treatment with darkness , the batch sown a week later were presoaked for 24 hours, the pots were covered with black pots covered with aluminum foil inside to keep any light out. Exactly when the last ones germinated, I don't know, since I left for Greece before there were any signs of life, but when I came back five days ago, there were some small seedlings, a bit pale, but with proper light, the colour of the leaves became normal almost immediately. The plants are much smaller than the non-soaked ones. I have taken a couple of photos this evening, and it is easy to see that the soaking/darkness treatment was not really impressive, the plants are much smaller. Unfortunately, I was a bit too generous with the first batch of seeds, the pots are really crowded, but in spite of this, the seedlings are bigger and seem very healthy, you can see that the leaves are bigger in the first photo (back row), in the second photo (bottom), you can also see that they are taller (those in the back) than the soaked ones in front. I had four pots of each category, the results were pretty homogenous within each group. It's not a proper scientific setup, but at least from these observations, there was nothing gained by soaking/darkness.