Socks just disappear.. I always thought the dryer eats them, but our dryer is about 15 years old and over the years it would have eaten HUNDREDS of socks.. I don't think I'm exaggerating.. HUNDREDS! No way that many socks could be stuck, clogged, eaten, whatever in ONE dryer without that dryer exploding.
I have NO F'ing idea where they go. sometimes I sit there and help my wife fold the clothes.. There is ALWAYS an odd sock.. IMO it is one of the mysteries of life and the cosmos.