[sp332]

You don't have to pre-clean dishes. This video is a bit long-winded but gets the point across. https://www.youtube.com/watch?v=_rBO8neWw04

One person doing one person's worth of dishes is pretty manageable. Once you get more people involved, or if you're getting a lot of utensils dirty while making something fancy, it can be a whole different story. Also, I think they use less water than washing by hand, but again this depends on how many dishes you put in there at a time.