Foam insulation simply wipes off a surface before it dries, but once it dries, the insulation is hard as a rock. There is no perfect way of removing foam insulation from surfaces such as a door. Removing the insulation requires multiple processes to break it down. Learn to get foam insulation off your door and other surfaces.
Put on your gloves and wear your dust mask. Removing the foam insulation may send tiny pieces of it into the air. Insulation can cause respiratory problems; do not attempt this without wearing a dust mask.
Use the plastic scraper to knock off as much of the dried insulation as you can. Some insulation is harder than others, and you have to chisel away at it with the scraper and the hammer. Keep working the foam until all but small pieces and residue are left.
Apply a small amount of acetone or adhesive remover to the hand towel. Gently wipe the area until the insulation residue is removed. Removing all the residue will probably require multiple applications.