The filmmakers of Fire In The Sky took a lot of liberties with the alien/spacecraft sequences--which is unfortunate, because that was the only 20 minutes that Walton could remember--but they did it to liven up the film and give it something the audience would want to see.
I was familiar with the case the day I walked into the theater, and I was disappointed when I walked out--and then became even more disappointed when D.B. Sweeney, the actor that played the part of Travis Walton, became almost vitriolic in his efforts to distance himself from the subject matter. "It was just a part, it's all a bunch of crap", etc.
Many of the abduction accounts I've read from John Carpenter, Leo Sprinkle, David Jacobs, Budd Hopkins and other researchers in fact do go into detail about the ships and usually they're quite clean and sterile.
I remember reading accounts in the books of Karla Turner and Leah Haley that the rooms were cold and smelled like the atmosphere had been generated only a short time before... like fresh airplane air. Something out of a hospital. I got the impression that the room where the humans are taken to be tested and sampled may only be there for the duration of the abduction, and then either recycled, or just turned off.
In cases where hybrids are present and human children are instructed to teach the others how to play, and the cases in which people are trained to play mind games and manipulate objects and symbols mentally, it seems like the abductees report fewer environmental aspects, so I don't know in those situations what they are like. In those reports, abductees spend a much longer time, and seem to go to the same room time after time, for the same activity. I don't remember hearing reports about the cleanliness of the rooms in those instances.
It may be that the female abductees have more of a flair for picking up on the details of the environment around them, or that they perceive the differently from the male ones.