Lap the rings! Even Talleys.
You can't lap them as they have plastic inserts that pivot and self-align everything without binding or leaving marks. One of the biggest reasons people use them is specifically because you don't have to lap them.
I've never had an issue with them slipping, but the suggestion to try the + offset inserts is a good one. Also, acetone will only leave the insert tacky for a few seconds, and once it evaporates could actually leave the insert more slippery, so I wouldn't try that. The suggestion to roughen it up a bit might be worth trying, as well as the thin layer of rubber cement.
