I can put clean 3/8" holes in up to 7 sheets thick of coro in one shot with my
paper drill.
Paper drills have hollow bits that are designed for drilling holes in
paper (think 3 hole punch but on an industrial scale)
The drill bit fills up with
paper as you keep drilling and eventually comes out of a hole at the top of the hollow bit and into a catch tray behind the machine.
Google "Challenge
Paper Drill" and lots of results will come up quickly.