Tip for removing radiator

I usually just stick a straight nozzle into a heater hose connected to the block, disconnect the other heater hose too, and run the water til it comes out clean. Then open the petcock, drain best I can and put 1/2 the capacity of the cooling system in straight antifreeze and then if need be, too off from there with straight water or else some 50-50 mix
While running the water hose if I can get to the block drain I leave that out while garden hose is on. If real nasty once I get it full on water I'll put something in like iron out and let it run a while (the engine not the hose) warm up and circulate the iron out then give it He11 with the garden hose again til clear.