the definition of scaliwag, according to the inventor of the word, is whores that got picked up by pirates and other sailors in port. Then got fu*ked in every oriface imaginable, using any and every available blunt object (specifically including the pepper shaker). When the whore was so utterly abused and disgusting that nobody wanted to touch her, the sailors would just throw her overboard.
A barhag whore, you'd never really date her. Also known as a "scally" or "scallies", they are good to have around at parties and good to occasionally hook up with. They're usually okay with this, no drama involved.
A scalywag is the opposite of a carpetbagger.
There were a bunch of scalywags in that bar last night.
He hooked up with some random scalywag.