oi. They are everywhere.
You gotta realize how many people come in to this website and others and say "whats a good tek".
Its all over the web, you can search this forum, the Dmt-nexus.org forum, or erowid - we all have plenty of resources for anyone.
bottom line; get bark - get some NaOH, pour NaOH in water, pour water over bark, swish around for a day, pour in naptha, swish around for a day, pull naptha out, freeze naptha for 2 days, filter, then throw everything away for legality's sake.