Teaching New Toy

I bought my dog a Tug-A-Jug to keep him busy (in addition to his Kongs) when I leave. However, I can't get him very excited about it. I put some kibble and chicken bits inside and gave it to him. He sniffed it and walked off. I shook it to show him how treats come out, but he seemed less than enthused. This sounds silly, but how do I teach him how it works? I thought the chicken would be a high enough value treat to get his attention.

We've had a very tough week with his SA (I lost the blinds and the doorknob) and I'm really trying to think of ways to keep him distracted. This toy would be longer lasting than his kongs. I might try a buster cube too. But how do you introduce them to the dog?