Sculling as a drill...Emmit Hine's articles and this really super cool video by a TI coach in Israel, Gadi, are different than sculling during the swim.
on one hand if you scull while drilling it's likely that you may bring it into your stroke. But of you are aware of what you are doing, as Gadi is...they can be super fun.
BTW I was taught an exaggerated S-pull and my sister in law is teaching her fellow triathletes that there are "3 sculling places" in the swim stroke. I want to fall over every time I hear her say that...but hvae to be careful of what/how I correct when I'm in her 'turf' at her health club.
Anyway ,check this out, drill #6 is one of my favorites to just play
Sculling GAmes & Drills