There are definitely people who will move every single thing out of a house in a weekend for free. That's how storage unit auctions are done, and buyers even pay for it.
Exactly, if you want a house empty you can make it empty just about as soon as you would like. The only question is who pays and how much. As you say - if it is junk you will pay some, if there are some things of obvious value you can come out ahead.