The person you replied to didn't explain the full concept - it's not just nail polish, it's nail polish with glitter in to create a unique pattern that the attacker wouldn't be able to replicate.

Unfortunately... I've seen a video of somebody defeating this concept before, not by trying to recreate the pattern with new nail polish and glitter, but by using a chemical (I can't remember what) that lets them, gently and very carefully, remove the whole layer of nail polish in one piece rather than having to break it apart, and then afterwards they stuck it back in place such that it looked identical. So it's not as secure an idea as it's often considered to be.

Edit: actually my memory was slightly wrong. The video I was remembering wasn't about defeating glitter in nail polish on a screw, but about "tamper proof" stickers which are made for the same purpose. I don't know for sure if nail polish could equally be defeated, but I suspect so. Here's that video (LockPickingLawyer defeating a tamper proof sticker): https://youtube.com/watch?v=xUJtqvYDnkg&