Well, think about this.....
you have crud loosened in that area... you are hoping that the movement of the air caused by the piston travel will blow it out...
but what if that piston is at the top of the stroke and about to head DOWN ?

This stuff has been discussed in the archives... you do not want any stuff to get stuck below the pintle in the precombustion chamber or in the tiny little holes in there.... it will really mess up the fuel dispersion and efficiency of that cylinder...

Using a vacuum seems like a better deal... and using the rental plan in the sticky above is really a better idea than taking a chance on breaking off the tip of a drill when you catch an edge... a drill and reamer work in very different fashions... AND you have the advantage that the correct reamer will be held straight by the threads on its base....