Oneshot. I started mine in Espoma organic seedling mix in Solo cups and placed them directly into the Hempy pots. I have no prior experience with the Hempy pots to determine the effects of having that cup full of dirt in there but it doesnt seem to be having a negative effect. Slightly digging into both the coco and perlite/vermiculite pots reveals massive root growth and the plants are happy.
That's the way to go. Start with a seedling mix like Light Warrior or Miracle Grow Seed Starter mix. They are mostly peat, and merge just fine with the coco.