I had best results with a simple glass testtube, sucking up the vapors with a glass 'reed'.
But this requires some skill, it's certainly not fool proof. Procedure:
1. Heat the tube in a not-too-small candle flame, keep it in the middle of the flame. Here it is cooler than above the flame and the heat spreads around the tube, heating the glass over a large area, preventing the DMT from running away, condensing on cool glass paers nearby (like in so many lightbulb efforts). The tube will get sooty but that's easily wiped off.
2. Exhale and then suck pretty hard as soon as it starts to boil. The air flow must be high to cool the boiling DMT and heated area of the tube. Sucking hard prevents burning.
3. As soon as the lungs are half full, take it way from the flame but keep inhaling. Don't keep it in the flame for too long, some of the DMT will burn or vaporize without being inhaled!
4. Keep it in as long as possible. Any smoke you exhale is a waste of precious DMT...
Don't cough!!!. The lungs can take it. If you start coughing, exhalation of the same caustic vapors make the poor throat cough even more - it's a self-amplifying process. After a while, the lungs have absorbed most of the harsness and you can exhale without problems.
My best DMT had no harshness at all smoked this way, on the contrary: divine and spicy like cinnamon, like an Elixir!
Most harshness of impure DMT is in the first whiffs in my experience, it can't hurt to pre-heat it a bit and suck off any harshness before the Big Hit.
The whole inhalation procedure takes maybe 7-10 seconds plus holding in for at least 20 secs. Repeat as required
Some DMT will condense on the tube walls. Although very pure, it's a waste of time chasing this with a flame. Recovering with a solvent once in a while is more sensible.
It's not the most popular way of administration but it works for me...
Here's a CG picture (not a photograph)