Is the substance really sticky like glue?
Yes it is very sticky. It kinda reminds me of tooth paste.
What is oil/water emulsion and is it more bad news for me?
This may be a long shot due to the apparent amount of fluid there. I have seen a very sticky, low viscous fluid like that escaping from an old coil pack and module before. It is sticky like plumber's pipe dope. Like I say, it may be a long shot; but check the back and underside of your coil pack and module for leakage.
Otherwise, like some others here have stated, it may just be a leak that is reacting with the environment after deposition.