basically a vapouriser get's to a certain temperature, and this vapourises the THC (in easy terms, it lights the THC but not the bud (although it vape's it not lights it
) but not the plant matter.
basically if you wre to take the weed out afterwards, it would be weed, but not weed, it would have little to no psychoactive effects.
and ledgrowing, that sounds like effort, might as well make your filter out of an 8th of weed, a realkly big filter, then once you've smoked your frist joint, your weed filter is shazzzzam strong