In reply to Reach>Talent: yea, you're right except this one doesn't do anything than what it says.
I have used it but my problem is, as you can read, I have lost all knowledge of how it was formed (not that there will be a likely situation for its application or use) and in a field test we had a Discovery on full torque pulling a tied of climbing rope: there was no rope deformity.
The fun bit was putting a piece of hand held, tightened cord against the tensioned rope and after three rubs it ripped the sheath and leaving only a few twines of the kern.
I'll keep searching, Andy