couple suggestions
1) put about 6-7 screens in there and put the dmt straight in with no leaf bed. if you weigh your dosage before you put it in the pipe and don't put way too much in there then you should be able to vaporize the entire dose before it melts through all of those screens
2) use ONE screen, but make a little filter/screen/disc out of chore boy copper scrubber. the main GVG thread has tons of information on how to make one of these chore boy filters. They work wonders for vaporizing without any dripping through.
3) take 1 part DMT and one part herbs... dissolve the DMT into a small amount of acetone. put your herbal mix into an appropriate container(depends on the amount of dmt/herb mix you are trying to make, i personally use a mixed drink glass) and pour the dmt saturated acetone over your herbal mix so the acetone level is JUST over the herb mix. leave it sit out for a few hours until all the acetone has evaporated and you no longer smell it. You now have herbs that are infused with DMT. You can easily load this up in the VG and vape it, or you can just throw it in a bowl or bong and smoke it like cannibis.
option 3 is my favorite way to smoke these days. It really adds a whole new vibe to the experience, depending on the herbs you choose to infuse. It also seems to make it much easier to dose, much easier to smoke(no real technique involved), and it seems to come on a little smoother.