Means to sell something, usually with a bit of hard sell, like spruiking a dodgy ute as a bargain and hoping nobody looks too close. It also pops up in flog yourself or I’m flogged, meaning you’ve worked yourself to the bone and you’re properly knackered. Handy verb for shifting old gear and describing how wrecked you feel after.
"Baz is flogging his Commodore on Marketplace, reckons it only needs a tune. Mate, it coughs like a pack-a-day tradie and the paint’s cactus."