That is indeed the meaning of the verb "to flog". Like you would to a horse in the 17th century, to make it go faster. "Flogging off" goods to make them move f

That is indeed the meaning of the verb "to flog". Like you would to a horse in the 17th century, to make it go faster. "Flogging off" goods to make them move faster is a relatively simple leap (and universal British slang).