I inject the Butt with Dr Pepper, Cover it with Mustard and add a Pork rub. Cook it low and slow. 10 to 12 hrs at 250. I use Hickory and spray it down with apple juice while its cooking, I like the spicy bite Hickory has. I didn't event this, I found it on you-tube. It is awesome!
GL, My neighbors crack up when they see me firing up the smoker at 4 in the morning. I do inject the pork twice, 12 hrs before smoking and again before it goes in the smoker.