Use a piece of wire to rake the big piece under the sparkplug hole then use the grabber W/light to get out.( this will take a few tries but you can get it)Thanks. I tried with small grabbers, but its head was too long (and not flexible) to move through the spark plug hole while the piston position is quite high.
I will need to manually move the crank, so I guess I need to undo the 7 other plugs and coils to turn it.. Would I need a lever or without sparks in holes (therefore no compression) it's doable just with hand?
Then blow out with compressed air. You can put a breaker bar on the crankshaft and turn the engine without having to remove other sparkplugs just the serpentine belt. Get the piston lowered to inspect with borescope to make sure you got everything.
You can try the vacuum if you want to waist your time. (no disrespect intended to members who suggested) Anything you get down the hole will not have enough suction to pull little pieces from laying beside the piston on the rings. (done it, did it, been there, done that)
You just need air nozzle that can fit down in the cylinder and you will blow everything to small to get with the grabber out.