Circle or Khale ?

Which to you use for Cats? Size's will vary I know. I'll will be throwing a 7/0 or 8/0 Circle Hook this weekend at the Cabela's King Kat Tourney up at West Lake Tawakoni east of Dallas this weekend. I saw on line that one outfitter sells this size hook and are "Chemically Sharpened". Can someone tell me about this sharpening process? thanx