what kind of gecko? i would suggest you getting another container and only making one whole on the side the size of a pencil. mark the top of the egg with a magic marker. go buy some vermiculite or hatchrite. weigh your container tare it on the scales weigh your vermic or hatch rite. then spray in as much water as you have substrate.make an indention that will cover the egg half way up.
in perlite and that container....your eggs will dehydrate in no time, good luck!