The Collaborative International Dictionary of English v.0.48:

Soap \Soap\, v. t. [imp. & p. p. Soaped; p. pr. & vb. n.
   Soaping.]
   1. To rub or wash over with soap.
      [1913 Webster]

   2. To flatter; to wheedle. [Slang]
      [1913 Webster]