If you're having the radiator cleaned, you don't really need the chemicals.
I usually hook a garden hose with a control valve to the upper heater hose nipple. Plug the hose you just unhooked. Disconnect the lower radiator hose and start flushing. Don't turn the sose on too fast, it will blow out the heater core and radiator. When that's clean, open the block drains and flush. Once that's all clean, remove the plug you installed in the heater hose and flush. Then let it all drain and put it back together.
