Coated With Slime

How do you deal with people who are in the habit of making pronouncements that are at once grandiose and vacuous? They often say things that are meant to make you feel good but lack the sincerity to pull it off. When every utterance is tinted with posturing and affectation, can you still get through to what they really want to say? When you look at them and see their smiles coated with slime, how do you suppress the disgust from showing on your face? Or should you?