Usually these monstrosities twist and the links, which are like
three in three, jump past the little indentations formed when the
chain is flattened, creating humps that prevent you just sliding them
back into position.
What luck, I just did one a minute ago so its fresh in my mind. This
particular chain was bright on one side, textured on the other. this
makes it easier because you don’t have to guess which way you have to
untwist. Start at the first twisted link. With a hand on each side
try to feed the link back into position, it of course won’t want to
go, so use an exaggerated rocking motion with your hands forming a V,
and open and close the V while you try to finagle the links back into
their homes. Takes awhile but it goes a little at a time. Once you
have coerced it back into reasonable position you’ll see that the
edges of the links are kinda ragged. Using a fixed ring mandrel,
strop the chain across a smooth face, shoe-shine like motion, this
helps nestle the links in more tightly. Lay the chain on a bench
block and rub with a burnisher, hammer if you want. then polish as
H-bones do this kinking thing for a living, its what they do best.
The kink will come back. I had a lot of practice in the 80’s, glad
they went out of style.