Yeah , I took apart a CDRW drive a few years ago, and there was a bunch of "lube" between the magnets and the focusing lens carrier. It was actually "connecting" the carrier to the magnets. In other words, it was "suspended" by capillary action, between the magnets and the coil of the lens focussing piece. (Now, I regret not taking a pic of it) I just thought it was some kind of "viscous damper" or something like that, but I've never seen anything like it ever before, or since (and I have taken apart LITERALLY thousands of electronic devices).
So maybe your drive had the same stuff, I dunno. But, like GBD suggested, I washed my hands straight away.
You never know what you're dealing with when you reverse engineer something made in China. Toxic substances seems to be their trademark.