I would look in the less than obvious places. It's there somewhere, that's a given. That gross smell will linger a long time.
I have sought out sounds and smells over the years when troubleshooting something by enlisting the assistance of a flexible clear plastic tube. About 3/8" ID or so works well. Buy it at Home Depot or similar by the foot.
When I have a weird sound to find I stick the tube in my ear and then move the other end around the area of the noise until I pinpoint it. Works like a charm.
I have done the same with smells. One end up my nose, literally. Shove it right up your nostril. Plug the other nostril by flattening with your finger. Stick the other end of the tube into places where you cannot possible get into to smell. Stick the tube in behind things under drawers, back of hard to reach cabinets, even down into the floor cavity where wires, pipes and such come out. Then sniff, sniff, sniff deeply to see if the odor is stronger there. Breathe in with the one nostril, breathe out with your mouth. By a process of elimination, you can get a sense as to the area the smell is originating from.
This works, I have done it many times. I do have a nose on me like a bloodhound and I can smell things any 100 people cannot. But its worth a try.
I had this problem last year with our TT. Where the flip is that disgusting smell coming from? I traced mine to under the kitchen sink. I got lucky, looked in the empty garbage container with no bag, mouse had crawled there, fell in and couldn't get back out. Easy fix.