Not only does this cleaner work in the Gevalia coffeepots, it works in all pots and does a better job on metal carafes than anything I've ever found. It comes in individual packets, so there is no guesswork about how much to use.
My metal carafe stains over time and nothing really works to get the coffee stains out EXCEPT this product. I place an envelope of the cleaner in the carafe, then run clean water through the coffeemaker to get the water hot. I suppose you could use boiling water from a teakettle as well. I let the solution sit for a half hour to an hour and when I pour out the contents (which are as dark as the darkest roast of coffee) the inside of the carafe sparkles.