Dumb question here, but how safe is this? I mean do I just spray the general area as it's running, I'm just afraid of it dripping onto the exhaust manifold and well..you know :doh:
As long as the engine hasn't heated up yet, the chance of fire is minimal.
Another option is to use a propane torch. Turn the gas on low and don't light it. then run the nozzle along the various places that could leak.