地沟油

地 = 也 + 土 : Dorothy Gale (di) hates the cleanliness of the space station, so she used an excavator (也) in the space station's bathroom (Ø4) to dig a pile of dirt (土) out of the ground (地) for a mud bath.

沟 = 勾 + 氵 : In front of the outhouse (ou1) Guy Fawkes (g) drew (勾) a photo-realistic comic (勾) of an open gully (沟) on the floor. The people are afraid to step onto it because it looks so real. They only start to believe Guy Fawkes that it's not as he spills a bottle of water (氵) over his chalk painting.

油 = 氵 + 由 : Maud Younger (y) is creating art in the outhouse's kitchen (ou2). She is painting a picture using oil (油) paint and occasionally using water color stored in a water bottle (氵). She is nipping a cuba libre (由) and from time to time even using her drink as color for her picture.