To accomplish something by brute force, without planning, elegance, or rework.
Often heard in IT organizations when referring to computer code that was poorly designed, and in need of drastic re-writing.
"How do you like the smell of my shit hammer!?"
"Don't mess with him, he will shit hammer your life away."
"Nothing like a good 'ol fashion shit hammer for breakfast."
Also know as "Trying to jam 5 pounds of shit into a 2 pound bag," and "Trying to put a bowling ball in a marble bag."
A second, less common usage, is used to describe a unit or kill team's decision to fuck up an enemy by brute force, in order to provide an educational experience for surrounding enemy units. Also called "Customer Service" or "Community Service."
Being on the receiving end of this particular kind of service is to be avoided, when possible.