There is a vile smell in my house that is exactly like dead rat in wall I’ve had to deal with in a prior place. There is zero under house access and no ceiling hatch. Bonus, it’s in the kitchen. We’re fucked.
This happened to me once in my old apartment - I went to the pet store and bought this odour eliminating spray which really helped dissipate some of of the smell! Was still awful though for a while so you have my condolences!