I thing I read somewhere if you add salt to the final rinse and then dry it helps set the dye. And didn't someone on the board mention a vinegar rinse????
I have found the dye catchers near the softner sheets at WM. But Joanne's has a similar thing, only reuseable for about 30 washes. Do you have a JA's near you? Hope you can get this solved, it must be really frustrating!