So have I! I have found these ever, all max level since there's so damn few:
1x Thunder SR with affliction, def (Thor)
1x Holy SR with affliction, +dbl (Sol)
2x fire R (Yamaraja)
2x water R (Ryu-Oh)
1x dark R (Nyarl)

Today I found Water SR Ring with only Affliction... not sure what I'll do with that. Leveling it to level 40 is a pain, and without a secondary effect it seems like such a waste... ... oh well, I guess I'll let my inventory fill up again and if there's no better target, Ryu-Oh is getting her set completed. Dear god she needs it, I'm pretty sure her Black Propaganda is lower success rate than what debuffs usually are.

Anyway, random is going to random. Maybe I'll get plenty of double Affliction SRs soon? Probably from Wind, where I don't have Oberon to give it to. Cybele is going to be happy.

I just wish that I had thought about using level 1 Rs with Drop Rate+ before you said it, I've probably enchanted a good amount of those away. Doh.