When I flush with a hose I supply through a heater hose and plug the other end of the heater hose then watch as it comes out the top of the radiator whith the cap removed. I also pull the thermostat with all other points of exit blocked and watch it come out the block. This way you are certain of obtaining a good back wash. Pull as many hoses you wish one at a time and be careful you do not over pressurize the cooling system as you change flow directions.