It doesn't matter if you smoke it, eat it, use a bong, smoke a joint, smoke a blount, smoke a pipe, or smoke from a vaporizer. If you consume marijuana you have consumed THC and your body will have to clear it and it can be tested for. The half life of THC varies in people from .8 days to 10 days. If you are saying you ate half a gram, you are probably in danger of testing psoitive for the next 7 to maybe 14 days. Eating or smoking really will not have much of an effect on how long it will take your body to clear it. More important factors will be body fat composition, metabolism rate, exercise, diet.