speaking from experience, the glass on lightbulbs is too thin. and just scorches the weed. you need to find something with thicker glass so it doesnt heat up to quickly and not all in one spot. i'd just dump the weed out the same way you got it in. if you break it, then there will be bits of glass that are small and you cant see. and just think what kind of damage that could cause if somehow that was inhaled into your lungs. prob. be best to throw it away, and cut your losses