Vinegar is great to get just about anything out.
I bought one of those downy softener balls, then fill it with vinegar and toss it in the wash. It opens up during the rinse cycle (somehow) and is great to get all the detergent/laundry soap out, super clean diapes and descent them as well.
Another good use for it is to soak any shirts that have stains in the underams. The stain is not usually from perspiration, but from antiperspirant. I just soak that part of my husband's tshirts in straight vinegar over night (or until I remember!!) and then wash as usual.
...course it's great to clean your house too...take away pet odors...disenfect, and it's SOOOO cheap.