Houses on cleaning products TV ads only seem to get patches of clean spots

While watching a TV ad for a cleaning product, viewer realizes those houses never really get full cleaned, they only have patches of cleanliness. Viewer would not want to live in, or even visit for that matter, a house where there are only clean patches; they never seem to actually clean the whole area in those houses riddled with dirt, scum, and all kinds of grease stains. It's really not necessary to leave back the dirt, grease and the like to see that the product cleans it up; it either will or it won't do the job.