A lot that you see in the stores, is just the effect caused by people playing with the settings, and the retail environment. Friends of ours has a 65" Samsung DLP and we have not seeing any ghosting, etc when watching sports or other fast moving programming on it. Usually what you get with DLP's is the Rainbow effect caused by the color wheel on the Engine.
The DLP is a "projection screen TV" as opposed to a "direct view screen" TV. Projection TVs tend to be dimmer and have viewing angle issues compared with direct view. The latter is due to screen gain which brightens the picture for those sitting directly in front at the expense of those sitting off to the side. Separate projector and screen setups (front projection) also has viewing angle issues if you choose a screen with gain.
The Rainbow Effect can be thought of as a kind of ghosting.
When cleaning anything including baby diapers, it is better to sweep off or scrape off as much solid and semisolid material as you can first. (1) Less cleaning fluid or detergent needs to be used, (2) Less of a mushy mess which in turn means that bleaches or disinfectants will be more effective.