You don't! Firstly - feeding him gunpowder is only going to make him sick ... very sick! In many places it is illegal, and certainly it would be considered as animal abuse. It will cause damage to the dogs internal organs - kidney, liver and stomach lining to say the least, and the only reason it may get aggressive is from the PAIN caused by swallowing a poisonous substance! It is messed up thinking. Secondly - why do you want an aggressive dog?
You shouldnt it's not safe
Buddy..you are sick and twisted to be cruel enough to make the animal angry, why you just hit it instead... *clicks report*
Why would you want your dog to be aggressive in the first place?!? Anway it's not going to be good for your dog, it'll just die or something if you feed it gunpowder (mean), which I or anyone else wouldn't want that to happen.