<A few nights later, Chrismas only a few days away now, I was tinkering with the tree, the lights flashing off and on, some working, some not, an unsolvable puzzle of physics only my wife could fix, when I heard the customary crashing down the stairs. A smell of vigorous deodorant(applied with a bicycle pump) filtered into the room.>
Maybe the narrator is making a joke that explains why his wife (if she is the person coming down the stairs) wears too much deodorant: instead of using the small sprayer that comes with a spray deodorant, she uses a bicycle pump, which sprays far too much deodorant on her. It's a hyperbolic joke, and not a description of what she really does.
Written in the spare elegant style he is known for, The Film Club is the true story about David Gilmour’s decision to let his 15-year-old son drop out of high school on the condition that the boy agrees to watch three films a week with him. The book examines how those pivotal years changed both their lives.
It is a better explanation for why the person is dousing himself in deodorant.