I worked at Mcdonnell Douglas years ago, and thats where I saw them use the electrical apparatus, it was specifically on the leading edge of a KC-10 tanker.
It was to correct the end of the front wing spar that had been bent over backwards during installation into the assembly jig, just the tip, not the whole channel section.
I saw it used again on a damaged lower skin, but never saw it used again after that.
I do know that an army of engineers had to look it over and sign it off before it was allowed to be done.
So in short, it was a structural piece but not a critical one really.
