Oops, posted in wrong place... here we go...
Very true, they will hatch no matter how you place it, however, I would not recommend placing it anywhere on the ground or close to the ground. The mantids need to be hanging. If they hatch on the ground, many of them (this also depends on species, as some are supposed to hatch on, or under the ground) will get deformed or end up getting stuck to the bottom of the container. As my friend Sheldon would put it... "momma knows best". If the female laid it on the lid (or that species generally lays ooths higher off the ground), then stick that sucker on the lid, etc.
In other words, placement of the ooth does not matter when it comes to hatching. Its basically the safety of the nymphs you need to be concerned about. Just make sure they have enough room.
On another note, I had a B. mendica ootheca hatch in the mail once. I have NO idea how in the world they were able to pull that off in the tight space they had. There was no room at all, yet a few of them still made it, even munched on a couple siblings on the way. Crazy...
-----
Mantis Kingdom