the radiator on my car is slow in circulation any good ways to clean out at home while still on car water is slow to filter down thru the cores
If the radiator passages are restricted, the engine cooling passages may also be restricted, here is an article and some videos showing one approach:
Many thanks to Steve Jelf for these!
I made this simple rig for flushing out of PVC pipe and a hose fitting. It replaces the pipe between the lower radiator outlet and block connection. Water from the hose backflushes through the radiator to the motor, then discharge down to the ground.