Wouldn't a random parametric EQ be exactly the tool you want for this? I often would lower the overall gain, and sweep one significant boost back and forth in the audible range until I hear the part of the music I'm looking for. Then it's just a matter of narrowing the range of that boost to really pinpoint the area(s) that troubles me. It's similar to the suggestion above, except that you play some music you know to sound annoyingly sibilant, and you can seek that instead of trying to identify sibilance as a single tone.
If the issue is caused by a headphone/speakers with a FR that emphasizes that area more than you'd like, then I'd go that road and ultimately just EQ the way you prefer.
But for a more case specific sibilance(a few select tracks or albums), you might want to use a "deesser" on those tracks to deal with them once and for all.