SWIM found that SWIY will end up with much better crystals if SWIY just leaves the container to sit after mixing FASA with acetone containing freebase. If SWIY shakes the container, crystals immediately precipitate out with considerable impurity. If SWIY leaves the container a day or two, much larger, clearer crystals form.
Do not stir or shake, as SWIY cannot unshake. This is the advice SWIM got during a dream, he moaned it out in his sleep and another SWIM recorded it and let me hear it. He may be crazy.