So after fumigating the house, everything was stable for a few days. Then I started to pick up moths on the second floor - which due to the numbers seemed to be coming from my office. A few turned up in the wife's sewing room.
So, I suspect a new genration was hatched after the gas. I then fumigated those rooms and sealed the doors. Now I have to keep watching the pheremone traops to see if a new batch hatches. In theory I should not have to wait more than 10 days for an all clear, but all it takes is one egg laying moth and I have to start all over again.
This is why it is really great to be able to seal off rooms and check them seperatly.