I am a bit new to this game, but have to do things myself, in the most economical way possible. Have decided to tackle one thing at a time. and would appreciate advice if there is a better/easier/cheaper way on each task. The first is the garage roller door. The other night I opened it to put out the garbage bins. It went up, but would not go down. The next door neighbour and I tried everything to get it down, then tried phone a friend etc, all no good. The garage opens directly into the house and where I live, security is a bit of a concern. So at some huge outrageous cost of hundreds & hundreds of dollars, an out of hours roller door mechanic came and finally got the roller door down. He gave me a big lecture about how stupid it was to spray Wd40 on all of the parts, said that was the cause of the problem, showed me the build up and said you have to remove it . This is what I am going to try and do tomorrow ( there is a lot of build up of the grime and it has attracted dirt and other inner city slime,to remove) What is the best way ? I have some Karcher, non corrosive degreaser. Will that work? Petrol?