Found something interesting:
"The one item that I found that works well is an electric "stick". It was
developed by a veterinarian and runs for a summer on 2 small batteries.
Metal loops on top give the deer a shock, something they never get used to.
A deer-attracting scent is provided with the sticks, along with cotton, to
place on the top holder on the stick to attract the deer, so they DO get
shocked and repelled quickly. This worked well for me, and I have used it
effectively for two summers