I have been in the business of selling catfish out of ponds for over 20 years and we do feed our fish floating. If the fish don't bite we make no income....When the fishing get tough we use 2 types of punch bait either Lewis King Select or Cj's they always seem to do the trick when nothing else is working.
We prefer a #6 treble or #8 Kahle hook with a 1/2 oz. slip weight. Cast it out but please do not tighten the line at all the fish will pick up the bait feeling no tension and usually catch themselves.
This is just my opinion but I do make a living selling catfish...

Ever thought about what they might eat when she isn't feeding? Sling in a minnow trap and I bet you will get some bait.