The purely imaginary method described below does work, but it works really really slow. SWIM's FOAF was able to extract ~100mg freebase alkaloids from 10g of MHRB. This method does not discriminate between the alkaloids that are extracted (j.spice, d., d-Noxide etc etc), this is however a subject of discussion.

The tek:

1) dissolve 5g of citric acid per 100ml acetone

2) take the shredded/powdered bark and cover it with enough citric acid acetone. Incubate in a warm place, gently agitating every so often. After 2-3 hours, filter off the citric-acid saturated acetone extract and set aside (this solution should have acquired the dark reddish colour of MHRB). Repeat 2 more times.

3) saturate acetone with fumaric acid. Acetone can hold ~20mg/ml fumaric acid if let for a day or so to completely dissolve.

4) Add the fumaric acid-saturated acetone in the citric acid-saturated acetone MHRB extract. One cannot put too much.

5) Set it aside and wait for 2-3 days. One should see a yellowish precipitate on the bottom.

NOTE: In step 2 one is making an acetone extraction and at the same time converting the alkaloids their citrate salt. After addition of the fumaric acid-saturated acetone in step 4, there is an interconversion of alkaloid-citrate to alkaloid-fumarate salt, like:

dmt-citrate + fumaric acid <-> dmt-fumarate + citric acid

citric acid has a pKa of 3.13, while fumaric acid's pka is 3.43. Fumaric acid is a weaker acid and thus in the above reaction one should have most of the dmt as a citrate salt and just a tiny amount as a fumarate salt. dmt-fumarate however is totally insoluble in acetone (while dmt-citrate is perfectly soluble), and it precipitates as soon as it forms. The insolubility of dmt-fumarate acts therefore as a "sink" and given time all of the dmt-citrate will eventually convert to dmt-fumarate and precipitate out.

6) wash the precipitated fumarate salts with acetone, then take them out and let them dry.

7) dissolve the alkaloid-fumarate salts in 5ml of tap water, then and then add saturated sodium carbonate to make the solution basic. The alkaloids will be freebased and the solution will become milky. In 3 days they will precipitate out forming nice needle-like crystal in the basic solution. At this stage, one can filter the solution (nasty procedure since the crystals tend to be sticky and waxy) and retrieve any left alkaloids by dissolving them in acetone.

8 ) Let the crystals dry, wash them with acetone (it removes any traces of sodium corbonate which is totally insoluble in acetone), evaporate the acetone and enjoy the product.

For the FOAF of SWIM 30mg were for a good STRONG experience.

Hi! Sorry to be so late.
I have never followed this tek, but I am no stranger to the fumarate approach to things. So here's my two cents on your questions:

In step #2 there is acetone in there. Acetone evaporates too quickly to get temeratures up high. Don't go past the 30 degree C mark, and never use a hotplate, I'd say.

I always swirl my fumarates, THEN filter them thought analytical papers. I wash them several times over, but I do this mostly to get rid of the xylene I use myself. Since there's no xylene here, once will probably be sufficient.

I have never had 'sticky and waxy' crystals. I use paper like for my fums. Maybe the temperature is a factor here. If one lives in a hot and humid environment it could be a problem. Perhaps putting in the fridge for an hour or so will help? Anyways, I live in a temperate climate and have always had brittle needles.

In my experience, the needles won't clog up your filter. Your mileage may vary however, so please tell us how you fare with your 120 um-screens!

Ah! Teflon(R). You know, I'm all for experimentation. But I don't relish the idea of risking getting some Teflon(R) in my spice. I'd rather take a little loss. And it's not loss at all, because I recycle ALL my leftovers, including my papers. Furthermore, the white Teflon(R) would make it difficult to see if there is still some scraps on it, and you could be looking at more loss than if you used glass.

Be sure to report back with anything you find, please?