I once bought a used pop-up, that was in nice shape, except for the massive quantity of silicone caulk that the previous owner had slobbered over every body seam. It was a pretty grim situation until a local dealership owner told me that they typically use Coleman fuel as a silicone solvent. It worked GREAT. In places where it was too tough to just loosen up with a wet rag, I used a fuel soaked compress covered by plastic wrap. IF you are not in danger of damaging painted surfaces and decals, Coleman fuel will remove all the silicone with little effort. Good luck.