Bought a new Bosch dishwasher to replace the aging Bosch that had no smells.
It was true that the mew machine had a bit of water inside (I think they're use-tested in the factory) and there was a sort of oil/machinery smell at first. I assumed it would disappear quickly with use.
After a month, I noticed a different smell and looked on the internet for solutions.
Here's what worked for me.
I had read that I should start using the bare minimum dishwashing detergent (I use Cascade liquid).
It was also suggested that I put a couple small pieces of copper tubing in the dishwasher somewhere and leave them.
After another month, I can report that one or the other solutions has worked. I had some copper tubing in the garage, cut two pieces, about 1 1/2 inches long (you can simply buy 1/2" copper couplings) and placed them at either end of the top rack over the tines. Dropped my detergent use to the lowest level line in the dishwasher. We only run the machine about once a week and only rinse the dishes quickly before putting them in the machine.
I've been checking and have not found any odor in the machine, even just before it's full and we run it again.
Not sure which method worked but it doesn't matter. The copper is out of sight and mind and it all seems to have worked, thankfully.