If you have allergies to birds that are dusty or produce constant powder, or you are just worried about it being all over the house, then the species of parrots you really have to avoid are African Grays, Cockatoos, and Cockatiels, as these 3 species are the ones that people are speaking of when they are talking about "powdery birds" or "dusty birds", or birds that effect people with allergies...
All parrots produce a bit of feather dust, but not to the point that it's noticeable. I've had my Senegal, Kane, for 2 years now, and I've not ever noticed any powder or dust anywhere from him at all in my house, and not ever noticed any on him either...Now Duff, my female Cockatiel, is so dusty that when you pet her you can see powder on your hand and you can feel it very obviously when you touch her, to the point that when you scratch her neck you can see the powder in the air around her.
I currently own a Senegal, a Green Cheek Conure, a blue Quaker, a Cockatiel, and several English/American Budgies, and I grew-up in a home that bred both English and American Budgies, Cockatiels, Green Cheek Conures, Sun Conures, and Jenday Conures, and the ONLY species that I've ever noticed dust or powder on were the Cockatiels...
As far as what a Senegal Parrot "smells" like, I never really noticed a smell on Kane, so I just went and put him on my shoulder and am literally smelling him right now, and he doesn't really smell like anything, lol...I have always thought that Budgies had their own, unique smell, and of course all of the dusty birds like the Cockatiels have their own smell, but as far as Senegals go, I can only speak about Kane as he's the only Senegal I've ever owned, and he doesn't smell like anything...nope, just checked again, I just smelled his back, his face, and his belly, nothing...He's totally confused as to what the hell I'm doing to him right now, and he wants nothing to do with it AT ALL...he's left the room...:33: