Just doing some solo-brainstorming - the humansense of smell is better than you might think - but of course unlike dogs or bears or similar we don’t put our nose right on the ground or on surfaces etc. If we did that then I’m sure we could pick up a heckuva lot of information, not as much as sniffer dogs etc but certainly far more than we can dream of at the moment.
Thus how about some sort of super thin straw for blind people that means they could sniff stuff far away? It’s probably a crackpot idea but at the same time I bet it’s the kind of crackpot idea someone has tried a prototype of - how did it work?
Smell works by volatile particles floating around in the air which manage to reach your nose and hit the receptors. I am going to assume that a cone will make it worse or have no effect, since you’re essentially reducing the possible directions that the scent can come from. Also, I can’t wrap my head around how this would increase the distance. Unless of course it’s a straw 100 ft long, and you somehow lift the whole thing and accurately put it up against a scent 100 ft away.
Human smell just sucks. To be anywhere close to an animal, we’d need to grow many more receptors. This might also need a giant schnoz. I am not aware of any scenthounds off the top of my head which have small or very little snouts (brachycephalic). A scenthound’s smell is millions of times better than ours (or depending on how you read that sentence and what your dog’s been rolling in, a million times worse). Wikipedia say dogs have 100x more receptors in a square cm than humans.
I not sure the human sense of smell is quite as bad as you claim. Bushmen and other non-industrial peoples can track and detect animals and other things in the environment by scent to a degree that it seems miraculous to people from industrial cultures. I think a lot of it is that were just don’t use what we have.