"I took this willy from Draco Malfoy by force," said Harry. "Can I use it safely?"
"I think so. Subtle laws govern willy ownership, but the conqeured willy will usually bend its will to its new master."
"So should I use this one?" said Ron, pulling Wormtail's willy out of his pocket and handing it to Ollivander. DH page 494
There was this one I read that someone else did that was aboot Harry thinking Draco's willy was a lot like Luscious', but I cant find it in the book.