Does de-esser software work, and should I be using it, or seeking a reason for the sibilance.

Answer 1

There are a couple of programs (Spitfish and Waves Resonance Deesser), but you may hear a slight "clamping" of the sound as you use it.  As a speech coach, I'm a little biased, but I think it might be worth your learning to control the "s" splash without technology.  There is a list of local speech coaches in the Voice and Speech Trainier's Association (VASTA.org) webpage.  Some, like me, work via Skype as well.  You can e-mail me through my website at www.deborahsalebutler.com and I'll see if I can find you more info if you want coaching via the internet or in person in your area.