After taking a quick look at your link, I'm gonna say you've been scammed. Pretty good one too, it has complaint proofing built right in. Mods may want to take a look as well, since the site is a marketing shill. I did not read the TEK there. IDK, the site says that (free base) DMT is smoked or injected IV and then the effects are described. That should've been a red flag to you right there.
Next time use one of the TEKS here, then you have the advantage of being able to communicate in threads or instantly via chat if you have issues, plus the methods are tried. I can't make suggestions on sourcing material other than to use common sense and protect yourself.
There's no real reason that basing your soup for three hours is going significantly increase yield. Nor would combining pulls have any effect.
Sine experientia nihil sufficienter sciri potest -Roger Bacon
*γνῶθι σεαυτόν*