Yep, WD40 is a proven winner for salmon and saltwater fishing. I've heard rumours that WD40 has a lot of fish based oils in it...
But I'm a ways away from spraying my box with WD40.
As for tobacco, I never used to smoke much on the river, and caught fish. Now I usually have a few cigars through my day, my waders reek of smoke, and I'm sure it transfers to my flies and gear, but well, I still catch fish.
I hardly ever use headcement, so can't comment on it, other than the smell it gives off does not instill confidence, so I only use it on flies I don't plan to fish.