I tried doing this Tek a few times with heat baths, warming the solvent and shorter wait times but only got poor results, about 200mg.
Then I just did all room temperature and longer wait times and it turned out better. I'm not sure about the cooking of the bark business, I've never done that.
My exact notes from also doing this tek are as followed:
50g Acuminata root bark
500ml water
50ml vinegar
Added to 1L flask
(wait 24 hours)
60g salt dissolved in 200ml boiling water
60g caustic soda dissolved in 200ml cold water
Added to flask
(wait 24 hours)
100ml Shellite added to flask and gently mix several times over 1 hour.
Pull Shellite with pipette into glass containers and put immediately into the freezer.
(repeat above step 6 times)
Leave glass containers in the freezer for 24 hours then carefully decant solvent and dry crystals.
Pull1 = 150mg
Pull 2 = 93mg
Pull 3 = 95mg
Pull 4 = 95mg
Pull 5 = 100mg
Pull 6 = 0-2mg
Total = 533mg
Nothing amazing but happy to hit 1%. Good luck to you mate 
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