''There's something captivating about Vince, the Shamwow pitchman. I always perk up when I hear those initial, outer-borough syllables: 'Hi, it's Vince wit Shamwow. Dis is fuh da house, da car.' A friend of mine--a guy who's never succumbed to an infomercial come-on--says he finds himself strangely tempted to order a Shamwow each time he watches Vince's spiel.''