Just a thought about seasoning a cooker.
It has bright ,shiney,stainless walls,and stuff bounces around.
Granma's old black iron skillet wasn't seasoned after the first cook,or maybe the 20th and neither will the cooker be.
Like the experienced cooks above said,cook until it is black and greasy and it will cook more consistent.
You can then probably cook chicken without adding any wood.
A pork butt to START the seasoning process will still be pretty good,but you can cook without it.
The goal is helping you get consistancy,and you have to start somewhere and it lets you see how the cooker is doing,right out of the box.
Hope this helps a little.