Hi
Well Siebe i’m inclined to say that it’s the same sutta,yes, and that all the 3 translations say the same just with different words.
The translation i posted is from Lal’s pdf book, i find it very clear, perhaps clearer than “development of the mind”… why ? Well because – imo – cleansing the mind is much more about “removing” than about “adding” and development suggests much more the latter (adding) than the former (removing)…