One pocket is like nine ball. You can string racks, but that's the limit of things.
In nine ball, Feijen ran a witnessed fifteen pack in about 2003 and I've heard from more than one source that Lassiter ran an unwitnessed 21-pack in the early 1960's. Also something I heard but can't corroborate, Dave Matlock ran a 28-pack on a barbox.
In banks, I watched while John Ervolino ran 15 and out in three straight racks of full rack banks (not all on the rack's first inning), truly one of the more remarkable feats I ever saw. I believe I heard that Eddie Taylor made thirty two banks in succession, also pretty unfathomable.
All that said, I'm not sure there are documented records in one pocket, nine ball or banks. But maybe we should be documenting this.