Your proposed use of the Alumaseal probably will not work. It takes circulating hot coolant with the particles in it to carry the stuff to the leaking spot. AlumaSeal WILL NOT plug up anything else, not even the small air vent ballcheck valve in the thermostat. It stays circulating, doesn't settle out in low flow areas or stuff like that. It is the same weight as the coolant so it just goes along for the ride.