Something like "I'm finding this conversation aversive, and I'm not sure why. Can you help me figure it out?" would be way more preferable.

It seems that preferences must vary on this one. This one seems much more potentially problematical because it pulls the other into your (already aversive) emotional world. It can work if there is already a huge amount of rapport and intimacy but the other more independent request seems safer.

Something in rationalist culture that I actually do like is using "This is a really low-value conversation, are you getting any value? We should stop." to end unproductive arguments.

I really do like whatever variants of the theme "Agree to d̶i̶s̶a̶g̶r̶e̶e̶ STFU" that can be made to work.