As a final thought for anyone thinking about buying oothecas.
First time for me, and it went about as well as it could have. Fairly simple, but takes long term attention (of a sort).
Just over a month inside the jar. Added some paper towel strips and the grass that came with the egg.
Every 4 or 5 days, I'd drip about a tablespoon of water in the towel/grass then reseal jar with the cheesecloth in place of metal jar lid. Took around a month to hatch from package delivery.
Kept it on top of my cable modem, it generates a tiny amount of warmth and was good enough to keep the jar humid but not wet/beading on walls.
Strangely, I think the bugs woke me up when they hatched. Looked at the jar and it was a fuzzy mess of birthing babies.
Super fun. Maybe try it with your kids?