LT1 coolant flush
 

What is the best way to completely flush my cooling system, including the heater core, to get any gunk out? Could I just undo the drain plug, and start the car and run it with the heater on, and run a water hose in the radiator, just do this until the radiator drains clear? I think that would be faster and much easier than the drain/refill 5-6 times method.

I just bought the car and don't know the last time it was changed, plus my heater does not blow hot air, it's not even warm. So I want to do it myself, to save money, plus anytime I take my car somewhere, they always fuck something up.

Any help greatly appreciated.

http://shbox.com/1/4th_gen_tech2.html#radflush Doesn't mention the heater core though.