Something I have noticed, and it took me a while.....
Try to NOT use tapwater, especially if it's city water. My water at my house smells pretty chlorine-y...and if it bugs me, I suspect the fish don't like it either. I now either use the cheap bottled water, or filter my home stuff. For me, it has definitely made a difference!!
I use rock salt and Mrs. Stewart's blueing, available at many stores in the laundry section. Also normally add a couple of squirts of herring oil, and a liberal spraying of WD-40. I do this the night before I go fishin'. All of this goes in a small lunch cooler (with a good lid

), and into the refigerator.
Generally, when I plug-cut, I leave the heads and guts right in the brine with the rest of the fish. I personally have never been much on attractor scents, however, I think all of the oil and WD covers up MY scent.
TR