If you have one of the front load HE washers you know that they can sometimes get stinky, mine does and the user manual tells you to leave the door open to let it air out but I can't always leave the door open because of where it is. If you read your instruction manual they tell you to run a special "cleaning cycle" once a month using bleach but a lot of people don't use bleach in their home, you can also buy special tablets that you put in the washer but again they are chemicals and I don't think they really clean the washer they just mask the smell with a heavy scent. I really needed something because mine smelled really musty so I searched the internet and found lots of articles, most of them suggested trying vinegar and or baking soda, so here's what I came up with and it works awesome.
I run a cleaning cycle (check your instruction manual to find out how to run a cleaning cycle) using vinegar in the soap dispenser then when that is finished I use baking soda and pour it directly into the tub part of the washer and run another cleaning cycle. It comes out smelling fresh and clean, depending on how musty yours is, you may want to repeat this several times to completely get rid of the smell. Once your washer is really clean smelling you'll only have to do this once in a while to maintain.
I love that it's inexpensive and I'm not using a bunch of chemicals to just mask the odor!
You might also like these: How to use vinegar to Clean your Microwave and use Vinegar instead of Jet Dry in your dishwasher.