blancher

noun

1. One who, or that which, blanches or whitens; especially, one who anneals and cleanses money, or a chemical preparation for this purpose.
2. A machine for blanching or whitening.
3. (obsolete)One who, or that which, frightens away or turns aside.

   “And Gynecia, a blancher, which kept the dearest deer from her.”

   “18 January 1549, Hugh Latimer, Sermon of the Plough And so even now hath he divers blanchers belonging to the market, to let and stop the light of the gospel.”