To Soap

1. (transitive) To apply soap to in washing.
2. (transitive, informal) To cover, lather or in any other form treat with soap, often as a prank.
3. (transitive, informal) To be discreet about (a topic).
4. (slang, dated) To flatter; to wheedle.

(to be discreet about): soft soap, sugar soap, soft-pedal, downplay