T.W.
Baking soda. If it's a large load you can use a 1/2 cup to 1 cup of regular baking soda. I buy it bulk at BJ's where the sugar and baking stuff is.
I put it in all of my laundry to help with stains and odors. It's a whole lot less toxic than bleach and some of the other things they have for laundry.
Otherwise, new towels.