Some techniques just aren't for everyone
I like sankaku jime, frankly. Many judoka and BJJ players do. It works pretty well, when everything goes right.
The problem I'm finding is that, as I try and work on it with my class, not everyone is having as easy a time of it. Sure, there's a player's level of inexperience that factors into it, but aside from that, I think there's an issue with their build. Judoka come in a wide range: small and large, young and old, flexible and tight, thin and stocky. And for whatever reason, this crew seems to be all the wrong builds for this version of sankaku jime (no offense guys).
Either that, or I'm terrible at teaching it (I hope that's not the case; I seem to be able to convey other things well enough!)
Upon reflection, I think there are two things that might be getting in the way: 1) not shifting their hips over to the side a little and 2) getting too much of uke's shoulder in the way. Although, with some, they just plain lack the physical "bendiness" for whatever reason.
Hmm. I'm going to move on for now, but I'll be thinking about it.