My 2 cents worth. Just seems to me that you are trying to cover your sent as we tend to fish more with reaction type baits, however, on slow presentation baits this sounds plausable. I have seen many a bass caught with WD 40 sprayed on the bait. Could be it just goes back to confidence in your choice of bait and sents. I have always been interested in this subject but have yet, as you seem also, to get any real evidence.