Is there a chew toy that would be suitable to be left inside crate all night?

[leac1801]

I use black kongs for mine to download into, and I have goat horns in the outside pen. 
 

Be careful with bitter sprays – we used to use them for rug chewers when I worked with horses, and no matter how careful I was it always got up my nose and in my eyes and it burns.