Hey I have a friend who just tried an STB on some Acacia Obtusifolia bark. He is certain it is obtusifolia. He wanted me to relay a few of his questions.
He followed the lazyman tek, did two pulls which were both left in for over 24 hours using around 500mL for each pull. After the first pull he added more lye.
The majority of the bark was ground down smaller than inch by inch pieces, and then some of it was not. It was left to sit in the basified water for around 3 or 4 days, so he thought that this should of been long enough, and grinding the bark further was not necessary.
When he separated the layers he noticed he didn't get all of his shellite back... and couldn't work out how to get it all so just left it, figuring there would be a decent amount in what he managed to get.
Well he did get a decent amount of shellite back, although not all, and then he washed the shellite with acidified water, then basified this water and extracted with shellite again.
This shellite was left to evaporate and around 30mg of DMT was recovered. This was smoked and DEFINATE effects were noticed, but 30mg was all that was recovered!
He then evaporated the uncleaned shellite from the pulls and then numerous amounts of goo was smoked, although there was only around 150mg of it, and although effects were noticed they were slight enough to be a placebo.
So what went wrong? He knows he has the right plant so it must be his extraction methods.