I was reading over all the different things about test tubes and the machine and the way the steel mesh acts as a heat sink, or something to spread out the heat and hang on to the liquid spice.

I was thinking why couldn't you use either a coarse sand or clean busted glass chips? The idea would be that the small bits would have the same surface area idea as the metal mesh and let the heat be more spread out and give the liquid a place to go. You would need really coarse sand, not like salt or sugar more like DampRid or sea salt.

I would think you could just leave it in the tube forever and not have to change it out like you have to do with scrubbers, it should be very clean and safe if you rinse it so there's no glass dust, and it's(mostly) free.

I got the idea from boiling stones in glassware, I just thought of it so figured I should post it. Let me know whatcha thinks

A little off-topic, but this got SWIM thinking, perhaps ceramic fiber? Supposedly ceramic fiber can withstand temperatures above that which a butane torch is capable of. SWIM's thinking of replacing the copper plug with a ceramic fiber plug in his piece if he can find the material easily enough.

Edit:
SWIM's thinking anywhere with industrial supplies will have ceramic fiber in the form of filters, insulation, or ropes. Otherwise, there are apparently wicks that are made out of ceramic fiber.

Edit, edit:
Perhaps this deserves its own topic. On topic, though: SWIM's not sure that most of the materials mentioned will necessarily heat rapidly enough. They'll hold heat for a long time, but SWIM's just not sure how easily they'll transfer heat. It's worth a try, though.

Metals are much better heat conductors, so any heat applied is distributed evenly. Besides that, I wouldn't fancy accidentally inhaling glass shards...

But when inhaling through a bong with the sandwich method, a protective layer of sand might work.

I thought about that, that metal is a better conductor but I figured if you only need say 200F to vaporize it that you may not need 600F or whatever lighters go up to for it to work...I guess the butane's go up to 2500F how is that not burning it up? Thin glass or chunky sand should heat up just as fast as the test tube glass, you wouldn't be using much, just a match head size pile or something. I also thought about sucking up the glass and thats why I would only use chips, I dont think they would get sucked up unless you were toking on it...which Ive never seen. The more air flow you have the less it will vacuum up anything in the tube also.

I dont even know, it may work for shit...just thought of it and thought I should post it to see what people thought. I also thought about glass/mineral fibers(believe it or not) but the only 2 I could think of were fiberglass and rockwool which both would be shitty because you couldn't help but inhale that dust, unless you water filter and that would still scare me.

I was really only thinking about using glass and then the chunky sand popped into my head...I wanted to either use tempered glass or something thin like a broken lightbulb or something Either way...just a thought