I would replace the batteries immediately. Only two things can "pop" like that in an electronic device, and that would be a battery or a capacitor. I doubt the remote has any capacitor large enough to make an audible pop if it blew, but a battery certainly might. And that wetness should not be there, so I suspect the battery is leaking. Make sure you completely dry the battery area, as that liquid is likely corrosive and you don't want it affecting the battery contacts.
Dan
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