OK, I'll bite. You want to clean your motor out right? So the inside of your intake manifold and valves are nice and clean right?
Well to do this really well can't be done all at once. GM actually makes a product called "Top Engine Cleaner" which works rather well, but IMO it's not the best way. Alcohol injection is. After a month of use, you could eat off of the interior surfaces of your motor.
Do NOT use ATF. Water won't do that much.