When you go to the Ancient monment (which is like the Ancient statue except its a finger) you need to switch to the White NMuzzle (default key to hold is "2" and you take the 40 degree nozzle (white). Now clan the entire statue (which is kind of a pain but with some patience you will make it).
SomeSome parts are tricky to reach, some are really easy. Since there is no real winning formula the only thing i can say is try different extensions (Default hold "1") and try whatever fits you and gets the job done. Also Freeing the washer with "C" (default) can help you get in those tight spots.
If you completed it in Career you can find this in Free play -> Locations -> CLean the Ancient Monument