it can be done, the complaints i read though is that you cant really measure the amount of co2, its kind of smelly, makes a hell of a mess if it blows up. any extra co2 would help though i guess. its warm water, not hot or you will kill the yeast. google homeade co2, you will find lots of info on it and its more commonly used for fishtanks. some places have detailed instructions on how to build, what kind of yeast, and amounts of sugar/yeast to use.