Your set up of the eggs looks fine. I use pumice as it seems to keep moisture away from the eggs, but holds moisture at lower levels in the deli cup and with the lid the humidity seems perfect. I started using it with crested gecko eggs and liked it so switched over. After I get it I wash it, let it sit in water for a half hour and then drain off all the excess water. Its cheap, easy, washable, and reusable - can't ask for better as far as I'm concerned.
Best,
Chuck