Does the writer at yahoo.com think that a rub and a barbecue sauce are one and the same?
Um, no. They’re two different things and when they’re the subject of a sentence, they take a plural verb (like are). Of course, describing a rub as “thick, chunky” is a little weird. I suspect the writer has no idea what a rub is; it’s a mixture of ground herbs and spices. Maybe next time the writer will read the actual article before writing about. Just a thought.