I feel like my ability to listen to that kind of stuff went through phases with my brothers too!
Phase One: Listened to it all, ate it all up, believed, was betrayed over and over = suffering and pain.
Phase Two: Tried to detach, change the subject, but when the attempt at recovery seemed REAL to me I let myself get sucked in a bit and felt I was "helping" or being "supportive" by listening or encouraging. Discovered it didn't make a difference to their recovery, sometimes they stay in it and sometimes they fall off and lie and start the BS all over = an unsettling feeling, like I have no control over my anxiety & resentment.
Phase Three: Actually detached. Achieved by practicing the wonderful art of the non-reply. If the conversation veers down those old familiar lanes again I just don't travel there with them anymore! I say "Hunh." and "Oh." and "I see, good for you." I am not cold or anything - just not engaging. I save my enthusiasm for topics I can have a valid conversation about. And when there is no engaging in any drama or what I might interpret as excuses or justifying etc, and my hackles don't get up, the whole topic goes away pretty quickly. I just can't help them get or stay sober so I have found it helps my serenity to just step off = peace of mind and not keeping track of anyone else but me!
It really did take practice.
Good luck-
Peace-
B