Re: Chunk of aluminum in Cylinder
for the shop vac to be even possible the intake and exhaust ports both have to be closed so you can even attempt to get enough suction in there. I doubt it'll work because you probably won't get a very good seal around the plug hole. If the exhaust port is open that would probably work. still gotta take the headers off and put the plug in.
Of course all this is moot if the valves aren't in either of the postions because you can't just turn the engine over manually.
I wouldn't use a coat hanger for fear of scratching the cylinder wall. A small extending pointer (or magnet) might work with something tacky on the end.
if you can't convince them, confuse them.