I haven't made it with duck but recently made a batch of antelope pepperoni sticks myself. I bought one of those "jerky pistols" with a pepperoni stick attachment. The seasoning I bought was also made by Cabelas and was called "pepperoni snack stick kit". After stuffing the casings, I just dried them in my dehydrator... just cuz it was easier than keeping an eye on the smoker.
The sticks turned out great.

Only thing I would do different is try to more evenly mix the seasonings into the burger. There is a noticeable difference between how flavorful some bites are compared to others.
I think the same seasonings would also work great for duck.
CC