Should II take HCl to help with digestion?

No. A normal stomach makes large amounts of acid, at the correct time, in regulated quantities, and stops acid release when acid is no longer needed. A person taking tiny amounts of acid would find no extra benefit, but a person taking larger amounts of acid would burn his mouth, throat, and esophagus (bad things!). Someone with achlorhydria (lack of acid) can ask his gastroenterologist for advice.