Marijuana is an illegal substance across most parts of the country, you should not be smoking it period, therefore the animal should not be exposed to it.
DO NOT EVER "LET" YOUR GECKOS SMOKE WEED OR SECOND HAND SMOKE.
GECKOS ARE TO BE KEPT AS PETS NOT YOUR EXPERIMENT. SMOKE YOUR DOPE OUTSIDE! SMOKE YOUR SESSION AT THE PARK, LEAVE THE ROOM AT LEAST. ITS DOWNRIGHT TORTURE.
The intentions to create a natural terrarium is to mimic their natural habitat. "Drugs, pollution, and loud noises" are not a part of that natural environment.