DMT fumarate is mostly just irritating, while freebase DMT burns like HELL. That’s why people use the fumarate for snorting instead of the freebase. Pretty much anything you snort is going to be irritating, make your eyes water, and make you feel a little ill. At least that’s how it is for SWIM. Even snorting sugar will make SWIM feel ill. (SWIM actually did that once by mistake).