TL, I used the wrong word. I shouldn't have used bribe. I understand what you are saying about helping them when they are doing the right thing. Fran used to call it "do to get."
The problem with my difficult child was that she would "do what we wanted to get what she wanted" which didn't include sobriety. And she would always use, "but, I am doing the right thing . . . therapy, sober house, 12-steps, etc." Unfortunately, she was just going through the motions to keep us paying for a roof over her head and food in her stomach.
I hope that isn't the case with your son.
~Kathy