I found that as a reforming Toxic player, If I pre-emptively mute all 5 of my teammates...
I've been having much more success! Now It's not optimal but It's baby steps. It's so hard to resist retaliation in self-defense for me that I find I win more games and can concentrate better if I do this..for now. Slowly working on not having to do this. I'm trying not to do this EVERY game but I can tell in champ select about 90% of the time when they will have nothing conducive to say anyway. Especially with dynamic queue disabled.