I have the same problem, my hair is about 2 and 1/2 feet long.(this is an older pic.) I shed alot and i wash alot of hair with my laundry. A few things that help is to:
- wash her clothes separately
- shake out the clothes when loading it into the washer.
- Have her comb it out in the morning before getting dressed, do it over a trash can.
- get her a satin pillowcase - it's easier on long hair, and there will be less in the bedding.
- I haven't ever heard of anything that will dissolve hair, but you can try cleaning the lint trap in the washer with every load.
- I also found that tresemme shampoo and conditioner for reducing breakage in hair works really well. it's about 3 or 4 dollars for a huge bottle at walmart or target.
Good luck, i hope this helps