Vacuum cleaners work by suction and suck up dirt. That would finally be correct usage of the word suck.
People do say it. I've heard it several times, and have jokingly said it as well.
While an open-ended vacuum does, literally, suck, one usually refers to the process, suction, specifically suction power when referring to the machine's action. One might be more specific/scientific refer to force of the vacuum if one were attempt to weigh the merits of various vacuum cleaners, although this is usually done by comparing relative measures of engine horsepower. Usually, of course, a practical demonstration is called for given. As for the negative connotations given to the term in common parlance, there are two possibilities: 1) It is an abbreviated version of the term more euphemistically stated as vacuums excrement. 2) It could refer to a negative memory of an adolescent experiment w/ a machine... The former seems more likely. But, as Fats Waller used to say: One never knows... Do one?
