If you're doing a STB tek with high enough PH, it should be fine. The lye will break that stuff open just fine. Even with an A/B tek you should be able to get the vast majority out. It just might involve longer cooks or more shaking.
I will let some of the local experts give you the detailed answer, but SWIM has done just fine with such materials.
"Curiouser and curiouser..." ~ Alice
"Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders. Do not believe in traditions because they have been handed down for many generations. But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it." ~ Buddha