Chronologically, SWIM decided to use fumaric acid saturated acetone (FASA) to salt out freebase alkaloids from non-polar solvent. In its philosophy, it sounds a bit like Cosci's tek.
So, the basified plant material was extracted with xylene. One may pull with repeated volumes of fresh xylene if one has a lot or re-use the same tiny amount (100ml for SWIM) again and again and again. SWIM opted for the second option because hates working with big volumes of xylene; it smells nice, but it is also alarm signal for the neighbours and whoever would like to stop you from doing what you are doing.
Anyway,
a) first xylene pull (coloured piss yellow) goes in an appropriate container.
b) FASA was added dropwise, xylene became cloudy due to the salted alkaloids. One cannot put too much FASA.
c) solutions was left overnite at room temperature allowing for the alkaloid-fumarate to sediment. Now one got them out of the xylene without the need to evaporate it!
d) Xylene was siphoned off and washed with plenty of water. This was done because this xylene had traces of acetone and fumaric acid that one does not really want. Water washed away fumaric acid and acetone, leaving back clean xylene (plus the yellowy plant oils that dissolved into it). This xylene was used for the second pull etc etc. By this approach one knows when to stop pulling since at some point there will be no alkaloids in the xylene to be salted out. it took SWIM 7 100ml xylene pulls to exhaust 240g MHRB.
e) fumarate alkaloids were washed 3 times with some acetone to remove any residual xylene and oily impurities.
f) Then they were dried in the oven at 70 Celsius until pretty hard.