A smooth talker is a good-for-nothing person.
More Japanese Proverbs:
Even a thief takes ten years to learn his trade.Japanese
Where there is no antagonist, you cannot quarrel.
Japanese
The smallest good deed is better than the grandest good intention.
Japanese
When you are polite, the others think they are wearing flowers.
Japanese
First the man takes a drink, then the drink takes a drink, then the drink takes the man.
Japanese
A gilt-edged visiting card often hides an ugly face.
Japanese