Love the Nockturnals, they’re all I shoot. Great luck, multiple animals with the same nock. Just too much good luck with them to use anything else.
I did have two that stopped working well after a few animals because of the dried blood deposits on the inside. However, I was able to rescue 1 of the 2 by soaking overnight in hydrogen peroxide. One of them had taken a bear, a deer, and a turkey! Unfortunately, that’s the one that couldn’t be recovered. It still lights up, but only fully when I press the button in a bit. Depress it fully and the light is faint. The hydrogen peroxide trick works well enough IMO to give it a whirl, as the worst you’re out is a nock that you weren’t going to re-use anyway.
I’ve read that people also will put a small bit of tape, or bow string wax over the hole in the nockturnals to prevent that issue in the first place. I’ll be doing that for my hunting arrows!
Joel