Would she be willing to try a cleansing conditioner? I use cones and I clarify once a week with a sulphate to get rid of them. My clarifying shampoo is from Great Clips and it rocks. It's 9 bucks, but I have had it for 6 months and it's not even halfway gone.
I hear anything with coco betatine will take them out. I believe that the Yes To products work for this.