I find the easiest ways to banish mold/mildew from the front loading washer is to leave the door open after using it, and to occasionally run a good sized load of towels on hot with bleach. Honestly, now that I always wash towels on hot I have far less mold/mildew, even without running bleach loads, as long as I leave the door open until the machine/door/seals are all dry. I understand the savings of running loads on cold, but from a practical perspective, that isn't going to help the washer stay clean.
Also, some machines have a small filter that needs to be cleaned out, and if we miss getting that done regularly the machine will start to smell. Cleaning is part of the upkeep of these machines -- just yesterday I cleaned the washer door and the seal.
I've never had mold in my dishwasher, but I do know that there are also filters and screens in them that need regular cleaning. We aren't great about it but DH gets it done every couple of months or so.