Fresh herbs will absorb most of the heat (converting water to steam).

As for multiple screens with dried herb vs. a copper mesh disc on a single screen with no herb, I can only say that the mesh works very well – it has a large surface area and limits the amount of DMT that flows toward the sides of the bowl.

With only screens it seems that a sizeable portion of DMT will flow toward the cooler glass. gammagore – do you notice residue crystallizing inside the bowl after use?

Nope, no residue.

Although ive only vaped xtals a handfull times in the last few months in my VG, I only smoke changa these days.

Also I try and clean my VG as often as possible, but I've never noticed any residue.

The dry parsley was definitely the key. I'll post my experience in the first experiences section. Thanks everybody for all of your kind help.