Us people in North America don't have easy access to drug labs etc like they do in Europe. So when we gauge, we can only just do our best to guesstimate percentage based on what clean MDMA is supposed to feel like etc.. I don't think Holly stating 90% was an attempt at spreading misinformation but more or less her opinion based on her experiences with MDMA in general (i.e. bad mdma with harsh comedowns etc)