We've had a few Bosch dishwashers in different houses over the years and I have NEVER done any more than scrape anything.
You basically remove any large lumps of food from plates, bowls etc.
Turn machine on to a normal cycle. Make sure that you use a decent detergent, I find Sun All-in-one Power (Unilever), Finish (reckitt benckiser) and Ecover all extremely effective. Also make sure you keep the machine supplied with salt for the water softener and with Rinse Aid to ensure good streak-free drying and your results will be flawless.
Bosch (and most European machines) have a primarily self-cleaning filter. During the wash the water is sucked horizontally across the filter and through the fine meshes removing all particles. When the machine empties, the water is sucked downwards through the middle of the filter and simply through a large grid that catches anything that's managed to get through. The pump can handle most normal sized food particles and they are simply flushed down the drain and the mesh filters are basically self-cleaned.
There is a wide mesh collar sticking up out of the filter, this prevents any larger items from ever getting into the filter system and they will sit on top of the filter tray at the end of the cycle.
Normally, all you need do is look into the bottom of the machine and you'll find any really big items of food e.g. beans, vegetables, pasta, nuts, etc that was not scraped off the dishes. You'll see these just sitting on the top of the filter system and they can easily be removed by just picking them off. There's no need to actually remove the filter.
The filter can be removed and checked and cleaned every month or so. However, most of the time I don't find anything in it!
Also, I suspect that this system removes more fine food particles than the old US-style disposal systems as there's no risk of fine particles being recirculated through the machine. It also means that the spray arms and jets are extremely unlikely to block up.
See the picture below for the filter centre unit. It sits in the middle of a large fine mesh tray.
