She had vacuumed everywhere, cleaned off my bedside table which had a nice layer of dust on top of my assorted gunk, cleaned out the drawers underneath the bed, washed the covers and the rug in front of the bed, dusted off the plush mice we got for our wedding, put the plastic mattress covers on, and so on.
So this night I got to try it out and see whether all that work made my nose happier. Well, kind of; most of the time, at least one nostril was open (though when I turned over onto the other side, it sometimes took a few minutes for the other one to open after the first one had closed up again). I suppose on the whole it's an improvement.
It does kind of suck that I can't breathe properly in my own bedroom, but we've done most of what we can do, so I'm not sure what comes next. Maybe wait and see what things are like over the next couple of weeks.
Oh, and the mattress covers do rustle a bit when you move, but not as much as I had feared. I didn't really notice it.