I have no idea what it is made of so I'm not sure if it's safe.

If I were you, I would reach back in to the tool box, grab a half inch deep socket, stick a screen in the bolt end and viola, you have an instant hitter. Undo the head of your kitchen sink and swipe the screen from there if you don't have one. When you are done with it, pick the screen out and return it to your tool box unharmed.