I never tried DMT but I once had a Salvia breakthrough while being on MDMA.
On friday night, I smoked weed and got to bed very late. On the saturday, after little sleep, I took a speed and went to another party. There, I got a small bump of K (it was my first try). Later, I took some MDMA and during the trip I got a proposition to try salvia. I said yes and smoked a long hit. After a few seconds, I heard a strange sound in my ears, I felt a feminine presence near me, there to care of me, very loving and positive. Then I got that awesome feeling: there was all and nothing, in fact just pure consciousness. And, then, I blacked out for a little while laying down on the bed. When I got back, I enjoyed beautiful CEVs. I remember one, an awesome pattern of a tree leave, with small tree leaves on all the edge of it, and all rotating, with so much details and beauty.