Use a professional Ionizer and wash the walls, ceiling, and any hard floors with TSP, the real stuff not the Phosphate free stuff.
Then primer the walls and ceiling with Killz and repaint.
This is what we did in my daughters house and you can't smell anything anymore.
The Ionizer may not even be necessary, it wasn't in my daughters house.
Do you know if TSP safe to use on kitchen cabinets?
