Toyota Repair: head gasket repair 91 forerunner 3L V6, head gasket repair, radiator hose

Question
i have just purchased a product called therma gasket (a two part liquid solution that you put into the radiator). in the procedures to apply the product it requires that i replace the thermastat and drain all the coolent and air from the engine. first is there a valve on the engine to drain air? second were is the thermastat located? have you heard of such a product working?  

Answer
I don't have any information about this product, this engine has no air bleeding valve, the thermostat is located in the housing where the bottom radiator hose connects to the water pump, there are three 12mm size nuts that attach the housing. Most of the time these products are merely a band aid or a short time solution before the real problem comes back.