It was a very cold morning in Ohio when I stepped on the school bus in 1971. Freezing rain was falling. I was in eighth grade. Inside the bus, it was about 85 degrees. 'Witchy Woman' by the Eagles was playing on the bus' stereo. That was the first time I ever heard the song. The bus had a powerful odor in it.
In 1978, while I was in the service, a friend of mine commited suicide with a gun in Texas. He was in his unairconditioned apartment for a few days before he was found. I was detailed to clean the apartment after the body was removed. The apartment had a powerful odor in it.
During the 1980's in Utah, I worked at a factory where we had a lot of CO2 venting. CO2 attracts mosquitoes. We used an insecticide that had a powerful odor about it.
I was given an ounce of Opium cologne for a gift once. This was the real stuff, not a knock off, about 75 dollars. It had a powerful odor (of course).
What I am getting to is that odor was blood. The best perfumes and colognes have a blood component to them. After I connected all these events together, I can tell what the quality of scent someone is wearing with just a whiff. It's really not hard to separate the animal products from the chemical products.
BTW, when I hear the song 'Witchy Woman', I am instantly tranformed into the eight grader on the stinky, hot school bus in Ohio.