About the only odors on a trap that you really have to worry about are food odors, and lure odors. These odors will elicit a digging response. The lingering odor of gasoline will not elicit a digging response.
This used to be a real bugaboo. Some trappers even suggested that you should have a seperate set of shoes for when you stop and gas up your vehicle so you wouldn't get gas and oil on your trapping shoes.
Frankly, I thought that "dips" would never catch on when they were first introduced because of this old gasoline bugaboo. But they did, and eventually after folks caught a few critters in their gasoline soaked traps (including some very respectable trappers), the old gasoline bugaboo just couldn't hold water anymore.
Again, the odors you need to worry about are bait and lure odors, don't get these odors on your clean traps. You can avoid this by handling your lures and baits with gloves, then handle your traps with clean hands, or handle your baits and lures with your hands, and put on clean gloves to handle your traps.
Leave the scent killer for the deer hunters -- although I doubt it does them much more good than it does for trappers.