I wish I could tell you a success story, but I attempted to germinate over 120 Passiflora seeds last January and had no success. I tried many of the methods you discussed including soaking in orange juice, milk, water, warm water and nothing worked. I think all the seed I had was old and not viable. I am trying a couple of new batches and started them this week. I understand Passiflora seed can take many months to germinate, but I used a seedling heat mat and kept the soil moist for five months. That should have been sufficient for germination to occur if the seed were viable.