@Clive131 I have invested in an ozone machine, you can buy them from Amazon for around £60.
I had a guest who spilt a bottle of perfume and after trying everything for 4 days, nothing would get rid of the smell. The ozone machine worked a treat. You do have to make sure there are no plants or anything "living" in the space, but close doors, windows etc. and turn it on and leave it and it does the trick.
I have used it quite often after cooking smells linger, or from time to time just for a general clean.
Good luck
Ruth