Our new fangled washer of the no agitator up the middle variety, has been found to get pretty stinky. Turns out this make and model has a design flaw where a few ounces of water wont drain out. Over time, and enough of my work clothes, it gets pretty ripe. The machine fells you when it's time to do it's special clean and rinse cycle so figured that wasn't it.
We got on the interweb/Gore Machine and found that this is fact the case. One Youtube tutorial later I'm taking the contemptible wash tub out of the damn thing after unscrewing and unbolting a fair amount of whatnot. Tub isnt too heavy but the angle isnt great for ergonomic lifting. Sure enough, thin layer of dirty water and some brown film on the wall of the lower tub. Didnt swab or break out the microscope to examine microfauna so let me live.
Wipe it spray it clean it put the damn thing back together. Interweb Gore Representatives recommend using vinegar with every other load to help clean and flush things out. You just put it in the bleach reservoir as you're putting things in. I also figure doing loads of whites on hot with plenty of bleach may help too. That and taking the contemptible thing apart a couple times a year as maintenance practice.
So, if the machine gets stinky, it could be the neat night crawlers you found but forgot about in your pockets but it could also just be the damn washer doing as it will.