On one of my hunts, I hunt out of a base camp, I generally make 2 trips in so I can have some comfort items, and meet my hygiene needs. My routine consists of unscented baby wipe, both morning and night. I will also use rubbing alcohol (I use a small spray bottle) at night on my pits, groan, hair and feet. Prior to doing this, I have, what I believe, seen animals wind me. The fact is that the animals we hunt, have a significantly better sense of smell than we do, their olfactory senses are much more developed than ours. Keep in mind that wildlife is attuned in picking out what doesn't belong in their environment, from hearing, vision, and smell.scent. From research we know they key in on the out of the ordinary. Some of the latest research on the hearing of deer finds that they have the same level of hearing as we do, but their ability to separate competing sounds, and pick up on sounds that are not usual in their environment is significantly greater than the human ability. That hearing ability is a survival mechanism, just as their hearing is. If your after prey that makes a living off of it's nose, like bear and pigs, I believe hygiene is even more important. My hygiene process appears to help. I'd say, it can't hurt, other than a little less money in your wallet, and a little extra weight and volume in your pack.
Obviously keeping the wind in your favor is a priority. However, we can see the wind, we cant see the swirls, bends, curves, and we certainly can not see how the landscape and vegetation alters and redirects the wind. Can a person harvest animals without attending to their hygiene, of course they can. But, why would you want to neglect hygiene if it is easily attended to. Granted, you can leave the tent in the morning, and sweat up a storm, and potentially negate any hygiene efforts you made. But today, we have so many options, from the silver tech clothing, to carbon, and so on; all which can help. We have the scent elimination sprays... But body odor can be like water in-that osmosis can carry it up hill. I'm sure many of you have experienced, as I have, a buddy with a week long BO build-up standing down wind from you while your chatting, but you can still smell their stench.
Like our tongs, and animal tongs, which have receptors that detect specific tastes, a deer's nose has groups of receptors that detect specific smells. Any given smell, once picked up by those receptors, triggers a signal in the animals brain. If the signal is associated with food, the animal might salivate, feel hungry... If the animal smells human odor, but is habituated to humans, the animal may not display any reaction, as the smell would be considered neutral. However, if the animal associates the smell with danger, it will undoubtedly trigger an desired reaction from the hunters perspective; triggering a heightened level of alertness, or flight, as in the fight or flight response in humans. The fact that wildlife, deer in particular, [since they are to topic of discussion (yes elk are in the deer family)] have significantly better olfactory senses than we do, and a greater ability to separate and identify different smells, we all as hunters should be concerned with our hygiene.
Habituation: I hunt an area from time to time, fairly close to some houses. The deer in the area are often found in the gardens of those houses (a safe area), but they move about their territory, and go up into the hills behind the houses. The hike up into those hill is pretty arduous. The opening of the season is generally while it is still very hot. So when I do hunt this area, I end up all sweated up. Despite this state of stench, I've had deer walk right up to me, yes including bucks. I have also been sitting, midday, having lunch with hunting partners, chatting it up, with no regard to the hunt, and had bucks just walk up to us. I chalk this up to the animals being habituated to humans, as I don't see this behavior in the deer I hunt in a wilderness area; nope, those wilderness area deer, both does and bucks, behave very differently, moving away from any human sound, smell, or sight.
Sure I've killed plenty of animals after climbing all over God's country, sweated up with a stench wafting up from my body. But I'd rather take every ethical advantage I can, and increase my odds of not spooking the prey I am after.