I've heard it about 12 years ago in the college. The names are changed to English (thay were Russian originally). ---- John and Paul were good friends. John was a smoker, while Paul could not stand tobacco smoke. So, once Paul came up with the plan how to help John to quit. When John forgot his pack on his desk, Paul took one cigarette, shoved it up his ass, kept it there for a minute and then carefully put it back into the pack. - Yuck! - said John smoking the cigarette, but still finished it. The next time Paul took two cigarettes and kept them up his ass for two minutes. - Yuck! - said John, but smoked both cigarettes to the end. The next time it was the whole pack and fifteen minutes. John wasn't happy, but still finished the pack. About three years later John quit smoking. And Paul still cannot get rid of his addiction.
(From the "Rest" of RHF)