When I hunted in Arkansas I would put on camoflauge face paint and clothing, a little deer scent behind the ears and between the thighs, get out at dusk leave at dawn.
This seemed to keep the deer away from me for bow through the end of gun season.
Forgot to mention the main tool to keep deer away, a combined Bow and Gun license with tags.
My understanding of the authentic Deer Whistle is the deer hear it from a greater distance and it gets louder as you approach, keeping the deer from being startled by your approach. They tend to keep munching on the side of the road if they are not startled. (Or maybe continue to stand in the middle of your lane if they are not startled.)
Coming home from Sturgis in the Wyoming dusk the deer just stood in the middle of the road as I honked and approached while slowing down, they didn't seem to see me until I was ten to fifteen feet away even though I had slowed from 65 mph to about 15mph. Maybe the headlights blinded them and they weren't afraid of the light but couldn't see the motorcycle. Once they saw/recognized the danger they took off in multiple directions.
Then it started a pissin rain. Dark, rain, deer, radar, rocks, pine cones, bed bugs, Pulp Fiction Hill-Billies, STDs. I love ridin.