I've been experimenting with the different FASA/I/W teks and FB conversions.
I found this to be the most efficient route for obtaining pure DMT (Fumerate).
DMT Fumerate:
1: Use Cybs A/B Salt Tek to obtain freebase DMT
2: Dissolve the final yield in acetone
3: Filter undissolved material using cotton in a funnel or syringe
4: Add FASA until no more clouding
5: Wait until the DMT Fumerate precipitates
6: Decant the solution, add fresh acetone to wash, decant again, dry
Freebase Conversion:
1: Dissolve DMT Fumerate in water
2: Add a basic solution with pH >11
3: Pull 3x with Naphtha
4: Freeze precipitate, decant, dry
Doing FASA on Limo /Xylene /Toluene results in a yield which smells like the NPS. Xyl and tol are toxic and very unpleasant smells to work with. Food grade Limo residue is safe for oral use, but some brands precipitate Fumeric acid. It also needs to be distillated (frequently) for proper use. In any case, the yield is contaminated and needs to be cleaned. This requires additional time and work.
I prefer the A/B naphtha freeze method instead. The FASA conversion is a good clean up step to turn sticky yellow, or dirty /contaminated DMT to clean bright yellow /white. Many plant substances don't dissolve in the acetone. These are filtered out. Many plant oils stay dissolved in the acetone after FASA is added. End result is clean DMT Fumerate which smells like pure DMT salt. Also, you know exactly how much DMT you have to start with, so you know how much FASA you need max. No need to worry about adding FASA too fast, Fumaric acid can't precipitate out in the acetone when adding too fast, as it does in NP solvents.
As for the conversion from Fum to FB, I didn't like any of the options stated here and in other treads. Some failed, others were a pain to work with, and all of them resulted in sodium carbonate residue in the yield. Easiest, safest and purest way to convert is to base with Lye, pull with Naphtha and freeze precip. Due to the small volume of liquid, 3 pulls were enough. No need to do much shaking. An acceptable amount of yield loss occurred, most due to discarding impurities and non DMT oils.
When doing FASA + FB conversion as a clean-up after an A/B, there are less oils in the FB yield. I found these oils sometimes had the smell of undissolved Naphtha. The yield after this technique hardly smells (of anything) at all.
The added value is that by freeze precipitating naphtha, you can recycle the NPS for re-use. You can also recycle the leftover Acetone into FASA by placing it back in a container with excess Fumaric acid. Quite sustainable..
The whole FASA/I/W road map is interesting. But imho the best way to use this innovation is after an A/B tek. This gives DMT Fumerate for storage and oral use. To convert back to FB, simply perform a mini A/B.
The disadvantage of this method is that the yields are not full spectrum (orange /red) or half spectrum (yellow, dark yellow), for the people who desire that. It also uses toxic Naphtha and corrosive Lye.