I too suspect its glue. As mentioned be careful of the index/detent springs and balls. Hold the fletcher upside down, should keep them from falling out as long as all spring tension has been removed. Don't forget, besides the index/detents there is a slot head retaining screw that keeps the receiver from just sliding out of the fletcher. It will need to be removed.
I prefer using silicone based grease as it doesn't "creep" and form a film all over everything as time passes like petroleum greases do. Onc eyou get it apart and all cleaned up, I think using the string wax is probably a good idea as it will most likely be silicone based.