Carbon monoxide is slightly lighter than air, it's CO2 that's heavier than airDCM aka methylene chloride decomposes to carbon monoxide - use it ONLY in a very well ventilated area...its also heavier than air and WILL collect in low spots..
Sorry it did not work Moggy always has for me, tin I have 2 years old tried it on a door of a Peugeot today took a patch off in about 20 min I put a sheet of paper over it to help keep it moist, suppose they could have changed formula.
Do you just slap it on neat etc or as suggested mix with paper paste to the right thickness ??