Aircraft paint stripper best by far. Use it at warm temps, out of direct sunlight if possible (that keeps it "wet" and working), agitate it in the working area with a brass brush or 3M green pad, don't try to do extremely large areas...its easier to do in sections, wear glasses, rubber gloves (not puney latex), don't work with it in the wind...one time will convince you of that, and keep a water hose handy for the occasional removal from your skin. Water kills it right away...so don't try to use it on water wet surfaces....do use it right away to stop skin contact problems.
"If it can't be reduced, reused, repaired, rebuilt, refurbished, refinished, resold, recycled or composted
then it should be restricted, redesigned or removed from production."