you know about the whoel salt n ISO method right? pour in coarse salt, and iso alcohol as a solvent, make sure most of the salt doesnt dissolve(use alot of salt)

shake shake shake.....

and its clean, also change the bong water at least every day, its nto healthy to leave water standing that long at room tempurature especially with dead plant matter etc inside it, and then inhale through it (bacteria duuuuude). ideally a bong should have the water changed every session.