I would think any type of "stick" treat would work. Some people like "pup-perronis", or you could use dehydrated meat as a stick. Basically anything that can stand up while the broth freezes should work ok.
Oh, just thought of it:
Make sure you use low-sodium beef broth. Regular beef broth is quite high in sodium and can result in too high a salt intake.
I'm firm - but fair. Mind the rules and enjoy your stay.
According to the Humane Society of the United States:
There are an estimated 3-4 million dogs and cats euthanized each year in the US alone! PLEASE - spay and/or neuter your pets!