When I notice that my students need a little extra "push" in the cleaning department, I use a very simply trick. Similar to my "mystery walker", I choose a "mystery paper" for clean up time. The floor will get covered in pieces of scrap paper pretty quickly when we are working on interactive notebooks or art projects. When it is time to clean up, I choose a mystery paper and tell my students that I will give a treat to the student who picks up that piece of paper. It is AMAZING how quickly those kids will start picking up paper when they know there is a chance that they pick up THAT piece of paper! HA!