Oh sweet, I didn't know that was a valid method.
I don't know how your DAW does track cuts/rangers/splits....but all I do is cut the vocal where the ess starts and also where it ends.
I'm not moving any of that around or anything, I've simply isolated that section of the track...and then I just lower the level for that spot.
Sometimes just 1-2 dB level drop, and the annoying ESSSSSS becomes a normal ess sound....because you want some of it to come through. I mean, you can't just cut it all out, because it will sound weird.
The thing with the parametric EQ is the same process, but the EQ adds a bit more focused control on specifc frequencies as opposed to just lowering the level on the entier ess sound you marked off.
So you mark/cut the vocal at the start and end points of the ess sound, same as above...and then with the parametric EQ only added to that small "slice", you apply a tight Q and dial in the frequency and level at the parametric that removes just enough to tame it...done.
It's surgical...but it's also manual, and some people get all giddy about the thought of having to actually do some manual work
...so instead they apply processing to the entire track and try to find a sweet spot that works on all the ess sounds...and you sometimes also end up affecting other shit too.
If you learn to do it manually...after awhile, you can slice your way through a track in like no time at all.
Hey...whatever works...everyone has their preferences.