Or, if you feel lucky you can put a shop vac with a very small nozzle up against the newly threaded hole and suck any stray pieces out. A good sized vac should be able to extract any fragments that might be in there. To make it easier to get them all out, you might run the piston to TDC first, that will make the area where any shavings go less deep and easier to clean out with the suction. You might also try to get it TDC when the exhaust valve is open so you get some air entering the bore to allow the vac to draw more air out.

Don