You know, when I started rereading your original post you didn't mention whether the "sticky stuff" was stuck on a metal surface or not. Since I am always more worried about anything that contains a solvent (propellants can fall into this category so anything that sprays out of a can is suspect) eating into a plastic surface or damaging some paints (not all were created equal) I would start with the most non-corrosive option first and work my way down the list.