So, I love the Kong toy. I really, really do. It's great to give her when I crate her during the day when I'm away at class or during homework time. But it seems that over time it's taken her less and less time to clean it out. Even if I freeze it overnight, she still finishes it in 40 minutes or less. My question to everyone here is there any "advanced" recipes that would last longer? Or would it be a good idea to buy a second kong to leave in the crate?