Dawson, in answer to your question, no, I do not use corn, or any other bait, on my jigs. I have tried it in an attempt to make the jigs more effective, usually when the fishing was a bit slow. But the results I have had always lead me to believe that bait is a waste of time and money on these jigs. I suspect that this may not be the case when vertical jigging, but I am talking about casting a jig and retrieving it in a more or less horizontal presentation. When fishing like this it has always been counter productive to add bait to my jig. It typically seemed that the strikes would come less frequently with bait. This may have been the case or it may have just been my imagination but what I know is true was that it took important fish catching time away every time I tried to bait up. If you get it right, when the fish are jumping pretty good on the surface, you will likely be getting at least one strike on every cast, without the use of bait. In my book, that's pretty tough to improve on.
I have not tried the siwash hooks to replace the treble hooks with yet but I have thought about it. I have tried clipping one barb of the treble hooks off with mixed results. The thought was that by eliminating one barb the fish would likely take the hook better and more importantly be easier to take off of the hook once landed. What I found was that by switching the factory treble's over to Owner's or Gami's, they work so well I haven't had the heart to change them and so never came to any real conclusions on this theory. If you choose to try the siwash hooks, let me know how it works out for you, I'd love to hear all about it.