Re: Removing adhesive non skid from deck
The solvent is usually naphtha based, like rubber cement, so covering the area with alum foil to give it a chance to seep in around the edges might help more than trying to use exotic solvents that might damage the deck. If you know what the non-skid is, try contacting the maker.
Heat guns are great but that may also require extra patience as the thick material will also slow the heat transfer. I'd expect it to work better than the solvent.