The pot that is holding the food needs to be FULL! I had been leaving head space so they were losing heat too fast.
Yesterday, I made a stew using a small pouch of pretty gristled beef chunks. I used fresh potatoes, frozen corn (thawed), dehydrated diced carrots (rehydrated), and dried mushrooms (broken up), beef broth powder.
I boiled it for about 12 minutes with the lid on. I took and put into the wonder box very quickly, and covered it for 7 hours.
The potatoes were cooked soft, not mushy, and the meat was actually tenderized. When I took the lid off and it was still at 169 degrees.
Tomorrow I will make BBQ chicken in a roasting bag to try the same technique . . . make sure the pot is full of water around the bag! I will try to take pictures as well.