I do two things.
1) I put a little loctite (blue) in the cap tube so that when I press in the cap finial, it stays in. This really helps stop clip spinning, but it does make future disassembly a little harder. Not impossible, but a little harder.
2) I put a small amount of loctite on the inner part of the clip ring. Not enough that I get squeeze out when things are pressed together. Just a light smear. This probably isn't needed, but it's easy to do and provide a little extra holding power on the clip.
I haven't had any pen with this approach go into clip spinning mode.
Ed