These are what I use for all my dirty clothes. I have a few, one of them being the Eagle Creek
here.
Basically, I pack all my gym clothes, undershirts, underwear, socks, and anything else I don't mind getting wrinkly in these compression bags. On the trip home, I use one or two of them for all my dirty laundry, and it keeps everything else in the suitcase dry and smell-free.