I ended up using vinegar in every wash with my diapers (mostly prefolds and covers) due to hard water -- that was what eventually worked to keep the smells away. I wouldn't start with vinegar though, wait until you (hopefully don't) find you need to do something else. Start simple -- rinse, wash, rinse, dry -- and only mess with that if necessary. I have never used baking soda in a wash for diapers but I imagine it would depend on your particular water situation. And doing baking soda AND vinegar at the same time is just a waste of money - you mix them and they make water and salt. If you're doing that, pick one or the other, or one after the other, not both at the same time.