Recently I lost my iPhone headphones. I didn't care much, as they were almost three years old, and I had a brand new ones. But today, while getting ready for work, I found them in the pocket of the pants I washed about week ago.
I was sure they wouldn't work, but guess what? They do! Probably the fact that they dried for days helped.
So I guees I have a spare pair of headphones now :)
Update, April 2019.
This time headphones with lightning connector were washed. And dried. Plastic and cable warped, so I won't be using them. But they are still working and can play music.