Deer will grow used to about anything like oder repellants, water sprinklers,flashing lights you name it. I control mine here but you may not be able to do it in our area with a 410Ga shotgun with target loads in it. At 30 ft that will not penatrate the tough hide on a deers rump. But it will certainly deliver a very strong long lasting memory. If you can manage to catch them out in the dark. the combination of the roar of the shotgun the muzzel flash and the sting of the shot is just about enough to keep them away from the area for a life time. I had a whoile herd scared to come into my area for a couple of years but a a cpuple bucks wondered in from other ares this year and I had to clarify the boundries to them.

I don't think that deer that come into yards are impressed by the smell of humans. If the smell of humans scared them, they wouldn't be up in your yard, where humans are living, touching the plants, leaving their foot smell all over the place, and making loud human noises.

Well why are hunters so meticulous about their body scent . Some after hiking to their stand / hunt area - change their clothes & put old clothes into plastic bags .

Because the hunting stand is in the middle of the woods where humans are unexpected, not a garden in a yard where people, dogs, cats whatnot are present all the time.