I think you have to use some other acid then acetic in your EtOH solution as acetic acid and EtOH form ethyl acetate (?).

I found some people don't even use acid at all for initial extraction. It may not be necessary for alcoholic extract as DMT freebase is soluble in ethanol. Ethanol will therefore pull both DMT salt and freebase. If you really want/need an acid step (e.g. for de-fatting), then you can mix your alcohol extract with acidic water, distill off the ethanol and continue with A/B extraction as usual.

I never tried that, but this method is described in one cactus analysis thread and works very well for mescaline.