I take it you saw the 'new' series? Whoda thunk it.... I almost felt sorry for a dalek.... well, until later in the series!
Hmmm, yes, I noticed that site appeared to be playing it close to the chest re cleaning... just thought it might have links that would get you the answer you seek. Still, if they've been growing it for 3000 years, perhaps they want to keep the monopoly?!