u/Alarmed-Painting-121

I've already ordered a replacement pair of headphones because its right at hips height and oil will get everywhere, but I need to know exactly what this is because I've never seen this before.

I think it could be some kind of oil to keep wires from oxidising but I'm honestly not sure. Nor do I know how toxic it is. Has anyone experienced it before?

Also I apologise if I didn't tag this correctly or this has already been answered.