The exploit is producing paw boards from boards you have sold to them already. It shouldn't be possible.
You can still probably overflow them with paw boards obtained "legally" (eg, from newly split boards, not sold), but you need to make them one by one. So it's quite different from just splitting boards (even if you are not good, and don't have great tools, before you could cut down trees close to villages, get plenty of normal and inferior boards, trade them for arrows and then, full of arrows, go to actually do some shopping).