a box of giggles or waterfall is another way of smoking weed it is used like a lung u fill the gawes with weed as you normally would but you have to make sure the bucket/bottle is filled with water. you then make a small hole in the bottom of the bottle so the water will slowly pour out. you keep burning the weed untill all the water has left the bottle, but if there is still a fair bit of water in the bottle which there normally is you can then put more weed on the gawes which will burn. you keep doing this untill all the water is gone. then attempt to suck in all the smoke that is left in bottle.
it is called a box of giggles because you normally use a LOT of weed in one of them and it will burn slowly making a very strong smoke which is most likely to give you the giggles.