Krishna says in Bhagavad Gita that controlling the lust is a lifelong struggle. Even for devotees, it is not that the lust goes away; what happens is when we keep saying NO to the lust, it’s attacks decrease; but it is always there. E.g. Srila Prabhupada explains it with an example of having a pet dog; you have always caressed him, loved him, played with him and acted for his pleasure; but one day the doctor comes and tells you that the dog has rabies and if it bites you, you’ll die; now you want to get rid of it, and you try to kick it out. But the dog comes back with a wagging tail. Seeing his tongue and submissive wagging tail, we say “After all he is not that bad; such a nice puppy, my puppy!” and then again he comes and sits next to us. Suddenly we remember, or are reminded, ‘Rabies’ and again we shoo him away; again he comes back. So the dog will not go away easily because we have showered a lot of love on him previously; therefore Srila Prabhupada says that we should beat him with a stick everytime he comes back. Here beating with the stick means saying NO to the temptations. That means when the temptations come, we should thoroughly reject them, then that is like beating the dog. But when we consider it partially then that is not real beating. Every time the dog comes, if we keep beating it, then one day the dog will stop troubling us.