I wouldn't want to do it like that but it should work just fine. (I'm a little OCD and would fear messing the DMT:HERB ratio up)
Honestly though, it should work just fine, just be sure to agitate the mix regularly as it dries.
May I suggest making a separate batch for now that is just harmalas infused into a carrier leaf? This would allow more control over the harmala dosage as well as allow re-dosing DMT without adding more harmalas into the mix. It could also serve to allow you to find your personal harmala sweet spot. I liked my mixes harmala heavy however it made redosing a challenge as I quickly hit a point where it went from heavy to too much.
>My favorite way of making changa was to add 500mG of Mullein to a shot glass
>Add the DMT on top (for me, 500mG)
>Pour just enough acetone on it to get the DMT to dissolve
>Add the harmalas on top (for me, 250mG)
>Pour enough acetone to completely cover the mix
>Stir the mix frequently as the acetone evaps
>Let sit for a few days to evap all the acetone
>Put in sealed container for an hour then open and smell to check for remaining acetone
>If no acetone smell, let sit a few more hours just in case, if acetone smell let sit open overnight and repeat previous step
A warning with the acetone vs IPA/ethanol is that harmalas do NOT like dissolving in acetone. With my mullein based changa, it caused the harmalas to stick to the fuzz in the leaf very well but not infuse into it. I made have a picture here somewhere.
As for the fourth question, I believe it should work however I would wait for someone to confirm. Is NaOH unobtainable where you are or do you simple not want to use it?
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