This is only be pertinent if you the low-end Bosch that was recommended by Consumer Reports: I followed someone's suggestion upthread about wiping down the rubber gasket at the base of the door where it closes, and sometimes the door too. I skeptically did this and saw an immediate improvement. For awhile I did it regularly, now I hardly ever remember - but the smell seems like it's just gotten much better. I do clean the filter thing as well as I'm able, but there's never anything but a tiny bit of residue on it. Like most of you, I really thought the smell was a deal-breaker. So there's hope. At first I thought I was going to have to run the machine every day, just to reset the smell, which was not in my plans.
Strange as it may seem, that bottom door rubber thing may be the culprit. I followed Josh's suggestion and cleaned it. It was not very dirty (perhaps because my dishes are rinsed of all food before going into the machine) so I didn't think the little bit of grayish scum (like what's in the filter) that I wiped off could make much difference ... but it's been a couple weeks now, I've repeated the process once more, and the smell seems to be gone. I'll remember to do this whenever I wash the filter.