That's too funny... a bug zapper of all things.
My favorite chemical free way to keep deer away is to keep a dog. But, my wife isn't a dog person. Of course, she wasn't a chicken person, either, so maybe I should just go out and get a dog.
Here is the list of non and pseudo non chemical repellents, from my dodgy memory:
Fragrant soap shavings
Human hair clippings
(The list of scent things is longer, I'm just drawing a blank)
BIG fence
Double row of not so big fence (see next for explanation)
Fence and an obscured landing zone to prevent jumping over (deer need to see the spot they intend to land)
Dog
Motion controlled sprinkler
Pepper sprays
Lawful deer harvesting (poaching is a pet peeve of mine)
What has worked for me depends on the weather. In a drought season, nothing (short of major fence project) will keep deer from eating your gardens since you'll be competing with a survival instinct. I just use a 36" 2"x4" fence. We lost a bunch of trees 2 years ago and the debris is stacked along the property line where the deer used to come onto the property, disrupting thier normal route.
Harvesting (deer) by my neighbors seems to have improved things, also. I can't take credit for reducing the numbers, I'm not accurate enough.
