Boris,
I obviously didn't explain myself very well. I agree with what you say but this is a cabincrew member. I was suggesting that if they are reticent about going to management then a word with the training staff first may get them to take the problem on and relieve the CC of the burden. If I was faced with the problem I would talk to the individual and insist that we both went to see the management concerned and would refuse to operate with the individual concerned. I know our company would do everything they could to help the individual and get them straight so they could resume their career so I suppose that would make the decision easier.
As has been stated above, the bottom line is that this individual has to be stopped from flying until their problem/habit is sorted out.