emptymind said:
I do not understand why anyone would make the machine instead of just using a chillum (or any pipe with a scrubber pad in the bowl). Is there some difference?
Most folks who have used the GVG say its without a doubt the best, but its expensive. I use a small glass bubbler. You can get a pretty cool small one for less than 20 dollars at most head shops, and the water will help cool the vapor making it less harsh.
I've smoked spice in a couple of different pipes (using scrubber), a bong, a 3 inch metal crack pipe (this was the harshest, but more effective than those previously mentioned) and the machine.. of these the machine (for me) is far more effective, less harsh and didn't cost me anything to make (as opposed to the bong, which I bought. The hash pipes, which were bought by others and the crack pipe... which was part of one of the legs off of a waveguide wifi antenna, which cost roughly £40).
The machine was my first choice, and worked amazingly... then I gave it away and that's why I had to try other methods, which still done the job but not so comfortably. Now I have a machine again and, until I no longer have it, won't be pursuing any other means of administration... unless I have a serious amount of expendable cash in which case I would buy a GVG (not that it is seriously expensive, but I would need to have many times the price of it spare before I would consider buying it)
I don't really understand the science of it, so can't properly answer your question... but for many people the machine is just far more effective and less harsh than other pipes.