As far as I'm aware, unless you're going the industrial/commercial way (and those are
awesome to use), you'll always have to rinse a bit before hand.
Of course, it depends. With just the two of us, and not cooking every day, and both working full time so eating at work often, we fill about one machine a week, so half the stuff is caked on. Doing a machine twice a day means nothing's caked/baked on, so you can get away with a lot more.
Personally, I prefer rinsing beforehand anyway, because it means the filter doesn't get as clogged, and you don't run the risk of having bacon fat stuck to your breakfast cereal bowl or vice versa.
That said, I've used many a machine over the years (not because they break but because I've done dishes in a lot of places
), and the lay-out is really something to pay attention to. I have the distinct impression the "cheaper" machines are made with such a lay out that they're simply not as effective and as good at cleaning as the more expensive ones - even if they technically have the same washing power. I know I can't put the plates right next to each other in the machine I currently use (my neighbours'), because they simply won't be clean, no matter what.