First wash, add one cup of vinegar to the detergent dispenser. Run a normal wash.
Second wash, add 1/2 cup baking soda. I sprinkled it directly in, but theoretically you can put it in through the detergent dispenser and add a cup of water to flush it down.
Toss those puppies in the dryer and make sure they dry completely.
Woo clean non-stinky towels! I probably need at least one more vinegar run to get these completely clean smelling. They were getting pretty foul due to poor circulation.
Theoretically you can combine steps by putting the baking soda in the detergent dispenser and the vinegar in the "rinse" dispenser (guessing softener section in my case).
It was cool this actually worked. I will start adding a 1/2 cup of vinegar to my softener dispenser in addition to detergent in normal washes & save the baking soda for occasional maintenance.