The idea is that you want to make a form of DMT that is more water soluble than DMT tannate.

In this case, addition of vinegar would be a good thing. It's my understanding that DMT acetate is more water soluble than DMT tannate. Also DMT acetate is very soluble in vinegar. However, this would also make a lot more impurities get extracted.

Citric acid would be good. DMT citrate is very water soluble and also very soluble in dilute citric acid. However, as with vinegar this would also make a lot more impurities get extracted.

You would NOT want to use hydrochloric acid. DMT HCl is poorly soluble in hydrochloric acid. This is one of the worst acids to use in this case. You’ll likely get the most impurities using this acid and the worst yield.

You would also NOT want to use fumaric acid either. DMT fumarate is one of the least water soluble forms of DMT. Yields would be reduced, however contaminants should be reduced as well because many fumarates are insoluble in water.

Of these, citric acid or vinegar are the best choices. They will produce the highest yield, but at the cost of more contaminants.