For the sake of portability, I bought a 3 inch glass one hitter from a head shop (the kind shaped like a cigarette), cut a piece of a Volcano Vaporizer Pad, and stuffed it in the bottom of the glass bowl.
To my surprise, it works as good as a GVG. Of course it does not vaporize, but the effects are the same.
Basically what I am trying to say is that the secret is in the Volcano Vaporizer Pad.
You can have a GVG, but only use a screen, or even a few, and it will still be almost worthless. You can use a weed pipe, and get minimal results as a result of inefficiency. But in both cases, if a Volcano Vaporizer Pad is used, the effects are perfect. Some here talk about steel or copper wool, but neither still compare to a Volcano Vaporizer Pad. One can buy 2 on Ebay for 10 bucks, they can then be cut to fit any device, and when used on most devices, the effects will work. The secret is in its design, there are many multiple layers stacked onto each other which catch crystals as they melt, a little falls through occasionally, but nothing in comparison.
So basically I think that the #1 secret in any DMT smoking device must be found in a Volcano Vaporizer Pad. There is no need to look any further.
Meditate before you venture, take it seriously, use it as medicinalโit is good psychotherapy if needed. Realize that you, the Earth, others, and the Universe are all one and the same process. Then take that knowledge back to become, as you already are, one with nature. Eternity in every moment. Divinity in every particle. All is one organism.