Filing nut slots on my own: bad idea?

Guitar Nut Files - Sports & Entertainment nut slot files I just came across this, If your looking to modify your nut slots, or create a new nut using nut files etc, here is an amazing video, nuts meaning poker I have a set of these from Harbor Freight, and I use them all the time for saddles, but I didn't think they were the right shape for nut slots

nut slot files productsnut-slotting-file-set-8-pcs-010-056-inch Not cheap I know, but decent nut files aren't