First of all, ouch and so sorry to hear that. What a disaster.
We recently nearly had a toilet overflow caused by my five year old son, followed by a ruptured sewage connector when emptying the full up tank - the pressure ripped it apart. Thankfully the dump station had a pressure washer to clean up the mess. It was then that I decided to move ahead with the installation of a composting toilet, something I had planned to do for some time. No more black tanks for us.
The smell will dissipate and once dried, whatever small amount of sewage remains in the belly pan will not be toxic. As the insulation is made from material that will dry out completely I would not worry too much about it right now.