Terryi...Try filling sink with hot water to submerge curtains fully. Add 2 cups of lemon juice and mix well. Soak curtains for 1 hr. then squeeze excess water out and hang in bright sunlight to dry. After air drying outside, machine wash again and tumble dry on low heat. I hope this works but may depend on material. Good luck!
Another option is to use 1 cup of dishwasher detergent and 1 cup of baking soda in hot water. Soak for 3 hours, rinse. If I am doing it in my washer, I usually use 2-3 cups of each so things are really submerged. Good luck!
Try using the newest Oxi-Clean, it is supposed to boost the whites.
You an even let them soak in Oxi-Clean, it is supposed to get the dingy out.
Oxi-clean is the best!
Oxi-clean works well. Use very hot water and let them soak for a long time. Using borax in the washing machine can also help.
You may also saturate them in hydrogen peroxide for about 30 minutes to an hour, then throw them in your washing machine and wash with a white vinegar rinse then dry.