I googled your problem and the vinegar rinse was recommended. There was also a recommendation to use baking soda in the wash water and another suggestion was to use hair conditioner instead of fabric softener. You might try washing again using only baking soda in the wash water and/or using the hair conditioner. I have not tried either method so you would be doing so at your own risk but I can see no problem with either. If you are unable to soften the material could the back be topped with a soft material so that what was next to the skin would be soft and cuddly? These are my only suggestions. I hope you find an answer. Is your friend aware of the situation?