To clean out

from The Collaborative International Dictionary of English v.0.48

Clean \Clean\ (kl[=e]n), v. t. [imp. & p. p. {Cleaned}
   (kl[=e]nd); p. pr. & vb. n. {Cleaning}.] [See {Clean}, a.,
   and cf. {Cleanse}.]
   To render clean; to free from whatever is foul, offensive, or
   extraneous; to purify; to cleanse.
   [1913 Webster]

   {To clean out}, to exhaust; to empty; to get away from (one)
      all his money. [Colloq.] --De Quincey.
      [1913 Webster]