Yes, you should open the mod up, take the screws out and pull out the board. The board is what controls your device, it looks like a miniature computer's motherboard. I used to work at a computer repair shop and I would see this all the time. Somebody spilled pop or something else sticky and it still worked so they didn't do anything. then a couple months later it stopped working, as a result of the heat melting congealed bits of the pop causing a short circuit.
It is a hassle, but worth it in the long run. Make sure you use something like 90%+ isopropyl alcohol because it evaporates rapidly and leaves no residue behind. Drench the thing in it then use a q-tip to get around all the components attached to it. the only thing I would avoid really is the LCD screen. The alcohol won't hurt it, but if you get a lot in it, it will take longer to dry out. Give it at least 4 or 5 hours to dry out afterwards, even wait overnight if your patient.
One nice thing about being pop though.. When taking it apart examine all the edges closely, anywhere that pop could have seeped through. If you don't see any sticky residue, then you likely don't need to worry about cleaning the board.