How about....
Remove the lid with the ooth still attached, place in a plastic bag then put in the fridge until your ready to hatch it.
Then get some cotton or fishing line and attach it to the lid. Then suspend the lid from a container or fish tank you can hatch then mantids in.
For the meantime you can keep the adult female in the same Geo-tank but put some netting across the top and attach with an elastic band.
Does this work for you?