I use 1 quart Dawn concentrated dish detergent to 1 gallon of "greased lightening" (from Lowe's) <> then do a final rinse with "409" if this fails then use easy-off oven cleaner, not a watered down imitation. This can be brushed on, wiped on or used in a pressure washer. for vertical surfaces use newspaper on a wetted surface then wet newspaper again as this holds the compound in place. If I learned nothing else in the Navy it was to clean, clean and clean some more!!!!!!